Pakiṇṇaka 21

The Buddha was staying at Sāvatthī. At that time, the bhikkhus gathered but didn’t know how to carry out an act of suspension. After they had a bhikkhunī carry it out, the bhikkhunī became doubtful and remorseful. She told Mahāpajāpatī, and she then went and informed the World-honored One about this matter. The Buddha said: “This is the respected bhikkhu sangha. Why did you carry out an act of suspension for them? From now on, it’s no longer allowed to carry out an act of suspension for the bhikkhus. If there’s no one among the bhikkhus who can do it, she may teach them how to recite. When the formal act is carried out, if they still can’t do it, and she prompts them from a distance, there’s no offense. If a bhikkhunī carries out a formal act for bhikkhus, she breaks a minor vinaya rule. A bhikkhu may carry out a formal act for bhikkhunīs without offense. This is called the rule on formal acts.