四分律比丘含注戒本 3.30

3.30

食者，是比丘應向餘比丘悔過言：「大德！我犯可訶法，所不應為，我今向大德悔過！」是名悔過法。

and eats it, that bhikṣu must confess to the other bhikṣus, saying: "Venerable sir! I have committed a blameworthy dharma, which ought not to be done. I now confess to the venerable sir!" This is called a confessable dharma.