Trinity Sunday

France, Paris. Bibliothèque nationale de France, Département des manuscrits, Grec 510 f.426v
Annus Dierus Sanctorum
Incomprehensibilis cogitatu.
Incomprehensible in thought.
Jeremiah 32.19
Hi tres unum sunt.
And these three are one.
1 John 5.7

The Liturgical Year by Dom Guéranger.

Romans 11.33-36

Matthew 28.18-20

Homilies Of Feasts And Sundays By Catholic Church Fathers by D. G. Hubert (Washbourne, 1901).

Sermons for the Sundays and Some Festivals of the Year  by Thomas White.

Explanation of the Epistles and Gospels for the Sundays, holydays and festivals throughout the ecclesiastical year, to which are added the lives of many saints by Leonard Goffiné (Pustet, 1880).

Goffine’s Devout Instructions on the Epistles and Gospels for the Sundays and Holydays (Benziger, 1896).

Abridged Sermons for all the Sundays of the Year by Saint Alphonsus Liguori.

The Catholic Pulpit: Containing a Sermon for Every Sunday and Holiday in the Year and for Good Friday (Murphy, 1851).

Readings for the Sundays and Holy Days of the Church’s Year (Bosworth, 1881).

Analysis of the Gospels of the Sundays of the Year by Angelo Cagnolo (Benziger, 1892).

Sermons for Children’s Masses, Accorading to the Sundays and Principal Festivals of the Year by Raphael Frassinetti (Benziger, 1900).

Sermons from the Latins by James J. Baxter (Benziger, 1902).

Short Discourses for all the Sundays in the Year According to the Mind & Method of the Catechism of the Council of Trent by John McQuirk (St. Paul’s Library, 1908).

Meditations for the Use of the Secular Clergy by Pierre Chaignon (Benziger, 1907).

Art

Concordantia caritatis, Morgan Library, MS M.1045, fol. 126v

Index of Medieval Art – Christ Sending out the Apostles, The Trinity

Music

Medieval Music Database

Cantus: A Database for Latin Ecclesiastical Chant

Jam sol recedit igneus

Customs & Devotions

Prayers to the Holy Trinity in the Raccolta

Concordantia caritatis – Trinity Sunday

transcription in progress

Morgan Library, MS M.1045, fol. 126v
DOMINICA TRINITATE
EST PATER EST NATUS FLAMMEN EST AB UTRISQUE PROLATUS :. HEC TRES PERSONAE DEUS EST UNUS IN UNIONE[?]
Matthew 28.18-20
VERBO DOMINI CAELI FIRMATI SUNT
Verbo Domini caeli firmati sunt; et spiritu oris ejus omnis virtus eorum.
By the word of the Lord the heavens were established; and all the power of them by the spirit of his mouth
Psalms 32.6
IN TRIBUS BENEPLACITUM EST SPIRITUI MEO
In tribus placitum est spiritui meo, quae sunt probata coram Deo et hominibus :
With three things my spirit is pleased, which are approved before God and men
Ecclesiasticus 25.1
DOMINUS AUTEM DEUS VERAX EST
Dominus autem Deus verus est, ipse Deus vivens, et rex sempiternus. Ab indignatione ejus commovebitur terra, et non sustinebunt gentes comminationem ejus.
But the Lord is the true God: he is the living God, and the everlasting king, at his wrath the earth shall tremble, and the nations shall not be able to abide his threatening
  Jeremias 10.10
EGO QUI GENERATIONEM CUNCTIS TRIBUO
Numquid ego qui alios parere facio, ipse non pariam? dicit Dominus. Si ego, qui generationem ceteris tribuo, sterilis ero? ait Dominus Deus tuus.
Shall not I that make others to bring forth children, myself bring forth, saith the Lord? shall I, that give generation to others, be barren, saith the Lord thy God
Isaias 66.9
ABRAHAM
TRES ABRAHAM CERNIT ?? ET HUNC ADORANDO SECUIT
VIDIT P[III]T[II]A TRES VITES STIPITE SIMPLA.
L[II] LUNA NOVATUS. ELEPHAS ILLA VENERATUS.
CINCEDULAS COMMEDO. [IIII]T/RHI TOLLIUS G LIBIDO