The transcription reads:
De Ampulla vitrea signo crucis rupta.Translation:
Gregorius. Recedente igitur temptatione
uir Dei quasi spinis eruditis exculta terra de
virtutum segite feracius fructum dedit prae
conio itaque eximiae conuersationis celebrae
nomen eius habebatur.
III. About the drinking glass broken by the sign of the cross.
Gregory: When the temptation had passed, the man of God, like cultivated land cleared of thorns, gave a boutiful harvest from the field of virtues. His name grew famous with the praise of his way of life.
In addition to the usual interchangeable letters (e.g. "segite" for the Classical "segete"), the text here also has an extra syllable in "eruditis," where a critical edition would give "erutis," a pretty common occurrence. The translation above uses "erutis."