Dharmaguptaka-vinaya 17.12

17.12

彼比丘不知犯麁罪不犯麁罪，後乃知麁罪，或有作波逸提懺者、有疑者，佛言：「不知，無犯。自今已去應如是結戒：若比丘知他比丘犯麁罪，覆藏者，波逸提。」

That bhikṣu did not know whether an offence committed was a gross offence or not a gross offence, and only later knew it was a gross offence; some repented it as a pāyattika, and some had doubts. The Buddha said: 'If one does not know, there is no offence. From now on, it should be laid down thus: "If a bhikṣu, knowing that another bhikṣu has committed a gross offence, conceals it, it is a pāyattika."'