He goes to the vestments, which should not be torn or mangled, but in good condition and fittingly clean and beautiful, and likewise having been blessed by the Bishop or another possessing the faculties, etc. (Tit. 1, n. 2).
On the origin of priestly vestments and why the Church desires her priests to wear particular clothing in the celebration of Mass.
In states and republics there are particular costumes required for many ceremonies: for rendering justice, for honoring the sciences, for rejoicing, and for mourning. It is no surprise that the Church makes us of particular costumes in her most holy and august ceremonies. In the Old Law God gave command concerning the sacred clothing required for the various functions of ministry, and though we are not subject to all the ceremonies of the Old Law, St. Jerome nevertheless infers the follow from what Ezekiel says about the Divine Service: “We must not enter into the Holy of Holies and celebrate the Sacraments of our Lord with the same clothes we keep for everyday use…. God’s religion has one set of clothing for the ministry, and another for use in everyday life.”
It is true that the Holy Mysteries, infinitely great in themselves, have no need of exterior luster. Thus in the time of the persecutions, the only concern was to offer the Holy Sacrifice with a pure conscience without looking for any special vestment. But most men find exterior and sensible signs necessary to draw them interiorly into the invisible grandeurs of the Mysteries. They must choose what will inculcate the greatest sentiments of respect. Cleanliness itself can suffice to inspire this respect. But when the Church was enriched by the gifts of the most powerful men in the world who had converted to the faith, there was no longer anything to fear in celebrating the Divine Service with a certain magnificence, because all the greatest things in the world come from God, and ought to be consecrated to his glory. The silver is mine, and the gold is mine, says the Lord of hosts in the Prophet, speaking of the glory of the Temple that is the desire of the Nations. This is the understanding that caused such magnificent temples to be built and adorned after the princes had embraced or authorized Christianity, and at the same time it became possible to use rich vestments for the sacred ceremonies. We read in Theodoret that the Emperor Constantine gave a robe to Macarius, Bishop of Jerusalem, with gold filigree to use while administering Baptism. From Optatus of Milève we learn that the Emperor sent out vestments to the churches, which he calls the Houses of God; and St. Gregory Nazianzen describes the brilliance of the vestments of the whole clergy. At the dedication of the famous church of Tyre in 313, Eusebius, Bishop of Caesarea, who wrote about the event, describes the vestments of the bishops who were present, calling them holy vestments that make their wearers worthy of veneration: “Friends and priests of God who are clothed in the sacred gown.” The vestments of those who performed a sacred ministry were regarded as distinguished from common clothing and were treated with reverence. Indeed, the priest Nepotianus, made so much of the tunic he wore while celebrating the Holy Sacrifice that he left it to St. Jerome in his will, because he had a particular veneration for him.
For some time this distinction of vestments for Mass was only observed as a matter of devotion, but later the Popes and Councils ordered that the Holy Sacrifice must be celebrated using vestments consecrated for the sacred action, and forbade, under strict punishment, the use of vestments for ordinary purposes. This is why the Rubrics foresee that the vestments are blessed by the Bishop, so that they are entirely set aside for sacred uses. According to the Liturgy of St. John Chrysostom, the Greeks bless each piece with a sign of the cross accompanied by a prayer each time they put them on. The Latins once did the same, as one can see in the Ratolde Missal written in the 10th century. The practice of vesting with certain prayers—which we will note in their terms, variety, and meaning—also appears in a great number of ancient Pontificals and Sacramentaries, observed with more or less regularity for the last eight centuries. The Pontificals and Sacramentaries written around the year 900 contain prayers for the Amice, Alb, Cincture, Stole, and Chasuble, and some of them add a prayer for the Maniple, which has subsequently been said everywhere since the 11th century.
Though these vestments were specially consecrated for sacred use, we can suppose that they were originally similar to the clothing used in civilian life. But since these often changed and the sacred vestments have also undergone some change, they subsequently became very different from one another. We will now look at the origin of these vestments, the changes that propriety and convenience have introduced, the intentions the Church has in recommending them to the sacred ministers, and the origin of the use of different colors for the various feasts.
1) The Amice, the Alb, the Cincture, the Maniple, the Stole and Chasuble, which the Popes and Councils have desired priests to wear for the celebration of Mass. The antiquity of the prayers recited during the vesting.
The order to be observed during vesting is given in Rubric and the Ordinary of the Missal in the order seen in the title of this section. Around the year 850 Pope Leo IV prescribed almost the same order in these terms: “Let no one say Mass without the amice, alb, stole, maniple, and chasuble.” These articles are found noted in many ancient sacramentaries from the 9th century, with these two differences: the first is that in one of the most ancient Roman Ordines, written in the time of Charlemagne, the amice is mentioned after the alb and cincture, a use conserved in the Churches of Milan and Lyon. The second difference is that the maniple is mentioned after the chasuble in the Regulation of the Diocese of Oviedo in 1050, in several manuscripts, and in various authors before the year 1200. This is observed by bishops even today, as we will see later. Here we follow the most common order, offering several remarks on each of the articles. With regard to the prayers reciting during vesting, they are found with some variation in innumerable church books since the 9th century.
The amice takes its name from the Latin word amicire which means to cover. It was introduced in the 8th century to cover the neck, which both ecclesiastics and laymen had left uncovered until that time. It must have seemed more decent for the neck to be covered in church. The clergy also wanted to conserve their voice and consecrate it to the Lord for chanting his praises, as Amalarius and the prayers of many ancient Missals give us to understand. A short time afterwards, the amice was regarded in many churches as a successor to the penitential sackcloth; in others, as an Ephod or superhumeral because it was too large to fit around the chest and shoulders, even though it bore no resemblance to the ephod of the priests of the Law. But in Rome and the greater part of the churches around the year 900, it was seen as a helmet that was placed on the head and left there until the very end of the vesting ceremony, when it was dropped around the neck just before beginning the Mass. This is still observed in Narbonne, in Auxerre from All Saints to Easter, and by the Dominicans and Capuchins. The ancient Missal manuscripts of the Royal Church of Saint-Quentin, which are around 500 years old and conserved in the archives of Greffe, record a prayer to be said while dropping the amice around the neck. It is possible that it was first placed on the head for a very natural reason, before putting on the other articles, so that later it could be adjusted properly around the neck after having put the chasuble on. It was also done for a mystical reason. The priest was to feel himself armed against the attacks of the devil, following St. Paul: “Take up the whole armor of God, and take the helmet of salvation” which is the hope of salvation. It is from here that the prayer we say today while putting on the amice is taken: “Place upon my head, O Lord, the helmet of salvation.” But since in the Roman Missal and those of a great number of the churches the amice is placed on the head first only to be tucked around the neck immediately after, we must not lose sight of the ancient mystical reason for placing the amice around the neck, which is that the amice is a sign of verbal restraint. Those who put on the amice for the Sacrifice, either to say Mass or to act as deacon, subdeacon, or any vested cleric, should know that this vestment warns him not to open his mouth except for the Holy Sacrifice, and that each one should say to himself that which Amalarius says, and many others after him ever since the 9th century: “I have placed a watch on my mouth….by this first vestment we are admonished to guard our mouths.” This is the meaning that the ancient Missals of Cambrai, which are still used occasionally, have perfectly expressed in the prayer that they prescribe for the amice: “Chastise, Lord, and govern my voice, so that I may commit no sin with my tongue, and that I may merit to speak only what is acceptable to you.”
(translated from Pierre Lebrun’s Explanation)
When pontificating in the papal rite, the pope wears a sort of second amice called a fanon, attested since the earliest Ordo Romanus, and worn rarely by Pope Benedict:
It used to be the custom to replace the amice over the head when exiting the sanctuary, making it into the hood or “helmet” mentioned in the vesting prayer. In medieval uses, e.g. Sarum, the amice was folded back over the chasuble, and the part thus exposed was embroidered or “apparelled” with a strip of rich cloth, forming a sort of high collar. The St. Bede studio has a good write up and pictures of this. The rubrics no longer tolerate this practice. Also, Lebrun does not mention another “literal” purpose of the amice, which is to protect the costly fabric of the outer vestments from being damaged by perspiration.
The use of the amice is usually said to be restricted to the Latin uses, but I’ve seen the Copts wear a similar hood called a “qalansuwa,” as you can see here. The black hood for a monk is received at his profession–where the ritual associates it with St. Paul’s “helmet of salvation”–and white is used for a celebrating deacon, priest, or bishop, who wears it under his larger round cap (’emma). It is usually embroidered with 13 crosses, a larger one representing Christ and the others the apostles.
On the qalansuwa, one blogger writes:
“The 12 crosses symbolize the 12 apostles. They should protect the wearer from evil thoughts and keep him clean. The seam on the top reminds the monks of St Anthony the Great, who always resisted the temptations, persecutions and plagues of the demons. The demons tore on his hood and damaged it. St Anthony then sewed it back together and a seam became visible. The monks in their ascetic life should never lose their courage and nerve, and in spite of all temptations, continue to fight unwaveringly for the faith.”
 Per quae discimus non quotidianis et quibuslibet pro usu vitae communis pollutis vestibus nos ingredi debere in sancta sanctorum, sed munda conscientia, et mundis vestibus tenere Domini Sacramenta…. Porro religio divina alterum habitum habet in ministerio, alterum in usu vitaque communi (Jerome, In Ezekiel, chapter 44).
 Implebo domum istam gloria…meum est argentum, et meum est aurum, dicit Dominus exercituum (Haggai 2:9).
 Historia Ecclesiastica, Book 2: “The holy robe, which the illustrious Constantine the emperor, in his desire to honour the church of Jerusalem, gave to Macarius, the bishop of that city, to be worn when he performed the rite of divine baptism, all fashioned with golden threads […].”
 Οἱ τὸν ἅγιον ποδήρη (Eusebius, Historia Ecclesiastica, Book 10, chapter 4). “Friends and priests of God who are clothed in the sacred gown and adorned with the heavenly crown of glory, the inspired unction and the sacerdotal garment of the Holy Spirit; and thou, oh pride of God’s new holy temple, endowed by him with the wisdom of age, and yet exhibiting costly works and deeds of youthful and flourishing virtue, to whom God himself, who embraces the entire world, has granted the distinguished honor of building and renewing this earthly house to Christ, his only begotten and first-born Word, and to his holy and divine bride.”
 Jerome, Epistle to Heliodorus: “Tears roll down my cheeks and, however much I steel my mind, I cannot disguise the grief that I feel. Who could suppose that at such an hour he would remember his intimacy with me, and that while he struggled for life he would recall the sweetness of study? Yet grasping his uncle’s hand he said to him: ‘Send this tunic that I wore in the service of Christ to my dear friend, my father in age, but my brother in office, and transfer the affection hitherto claimed by your nephew to one who is as dear to you as he is to me.’ With these words he passed away holding his uncle’s hand and with my name upon his lips.”
 Vide Baron. an. 260, n. 6. Conc. Brac. can. 2.
 Euchol. Graec. p. 59.
 Lib. Sacram. Eccles. Turon. ante an. 800. Marien. tomo 1, p. 343. Sacrament. Ms. Trevir. ad Casulam, ad Fanonem.
 Ordo Romanus I, pg. 7.
 Missal. Ambros. 1482, 1548, 1560.
 Missal. Lugd. 1520 and le Recueil des Ceremonies de l’Eglise de Lyon (1702).
 Conc. Coyac. Conc. 10. 9 col. 10. 4
 Sacramen. Ms. Trev.
 These prayers are found in the ancient Mass printed by Flaccus Illyricus in 1557, which seems to me to be a collection of prayers taken from the Missals of many churches of Germany toward the end of the 9th century, rather than the Ordo Missae of any church in particular. These prayers are also found in a Pontifical of St. Prudence, Bishop of Troyes, and in two eight-hundred year old manuscripts from Moissac, and of St. Gatien of Tours, given by Fr. Martenne (vol. 1, pp. 525, 533, 536); in a Sacramentary manuscript of Treves, written around 990 and conserved in the library of the Oratory in Paris; in a Sacramentary manuscript in the library of the Church of Noyon, around 800 years old; and in two manuscripts in the Royal Library, one of which is a Pontifical from the Church of Seez, written around 1040 (n. 3866), where the Mass is the same as the one give by Father H. Menard in the title Missa vetus ex codice Tiliano, Append. ad. libr. Sacram. p. 226; and the other is a plenary Missal written in 1060; and finally in a very great number of other later Missals. There were only a very few churches in the 12th century where the vesting took place while continuing the prayers of preparation, without reciting particular prayers for the vestments.
 Amalarius, Book 2, chap. 17: “Amictus est primum vestimentum nostrum, quo collum undique cingimus. In collo est namque vox, ideoque per collum loquendi usus exprimitur. Per amictum intelligimus custodiam vocis, de qua Psalmista dicebat: Dixi, Custodiam vias meas, ut non delinquam in lingua mea; postui ori meo custodiam. Et in alio psalmo: Pone, Domine, custodiam ori meo. Amictus ideo dicitur, quia circumiicitur. In isto primo vestimento admonetur castigatio vocis.
 Missal. Camerac. Atreb. etc
 In the ancient Mass printed by Illyricus, the priest said while changing from his common habit: Conscinde, Domine, saccum meum, et circumda me laetitia salutari. According to the ancient Missals of Liege, of Aix-la-Chapelle, of Rennes, etc., this prayer was said while putting on the amice, but after saying Exue me, Domine, veterem hominem while removing one’s common habit. This is what bishops still stay when taking off the mozetta. The saints regarded the common habit as items of humiliation and penitence, because they were given to man after his sin: which is why the Church wishes her children to take joy only in the clothing that she has us wear for the Divine Service. This is what caused her to take this prayer Conscinde Domine from Psalm 29, where we read Convertisti planctum meum in gaudium mihi, conscidisti saccum meum, et circumdedisti me laetitia.
 Ad Ephot. humeros et pectus meum Spiritus sancti gratia protege, Domine, etc. (Missa Illyrica; Sacram. Ms. Trevir. etc.; see the fragments attributed to Theodore of Canterbury, pg. 38).
 Induite vos armaturam Dei… et galeam salutis assumite (Ephes. 6:13, 17).
 Impone, Domine, capiti meo galeam salutis ad expugnandos omnes diabolicos incursus.
 Posui ori meo custodiam… in isto primo vestimento admonetur castigatio vocis (Amalarius Book 2, chapter 17)
 Ad amictum per quem admonetur castigatio vocis. Castiget et moderetur vocem meam custodia tua, Deus: ut non delinquam in lingua mea, sed loqui merear quae tibi sunt accepta (iMissale Camerac. 1527 and 1542).
 See Vopiscus in hist. Aug.
 Dealba me, Domine, et munda cor meum, ut in sanguine Agni dealbatus, gaudiis perfruar sempiternis.