This page is awaiting cleanup.Below is a description of the cleanup required: Which version is set by whom isn't very clear yet
Hymn at Vespers in Lent, attributed to Pope St Gregory the Great. A revision in 1632 by Urban VIII changed lines 3-4 (among others) from "in hoc sacro jejunio
fusas quadragenario." to "sacrata in abstinentia
fusas quadragenaria"; the 'restored' versions of Solesmes apparently have small variations as well.