Happy day of union sweet. C. Wesley. [Christian Unity desired.] From his Short Hymns, &c, 1762, vol. i., No. 995, slightly altered into the Wesleyan Hymn Book, 1780, but omitted in the revised edition, 1875, in favour of "True and Faithful Witness, Thou." This latter is a cento thus composed:—
Stanza i., Short Hymns, 1162, vol. i., No. 988, on Is. xi. 5.
Stanza ii., Short Hymns, 1162, vol. i., No. 995, being the second half of the former hymn, "Happy day," &c.
Original texts in Poetical Works, 1868-72, vol. ix. pp. 385 and 388.
--John Julian, Dictionary of Hymnology (1907)