佛說目連問戒律中五百輕重事經 1.108

1.108

問：「受歲時，尼來界內求索受歲，應與受不？」答：「二尼以上得。一不得，所以爾時，以尼獨出界犯重故。」

Question: "At the time of pravāraṇā, if a nun comes within the sīmā seeking to observe pravāraṇā, should she be permitted to observe it?"
Answer: "Two or more nuns may. A single nun may not. Why so? Because a nun leaving the sīmā alone commits a grave offense."