Genre: 
Full text: 
O lux beata trinitas et principalis unitas jam sol recedit igneus infunde lumen cordibus | Te mane laudum carmine te deprecemur vespere te nostra supplex gloria per cuncta laudet saecula | Deo patri sit gloria ejusque soli filio cum spiritu paraclito et nunc et in perpetuum
Feast: 
Fulltext source: 
https://www.preces-latinae.org/thesaurus/Hymni/OLuxBeata.html
Notes: 
cf. 008358.3 for the 1632 Urban VIII revision of this hymn, which begins differently and has extensive other differences
CAO sources: 
SL
CAO: 
8358
AH volume: 
51
AH item number: 
40