Trinity Sunday

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