Pakiṇṇaka 11

The Buddha was staying in Sāvatthī. At that time, the bhikkhunī residence was separated from lay people by a wall. A lustful bhikkhunī patted her vagina with the hand. When the husband heard the sound, he said to his wife: “What’s this sound?” She answered: “You don’t know why one makes this sound?” Her husband said: “This is the sound of these renunciates who practise celibacy, have a lustful mind, can’t restrain themselves, and pat their vagina.” When the bhikkhunīs heard this, they for this reason went and informed … The Buddha asked: “Did you really do this?” She answered: “I really did this.” The Buddha said: “From now on, it’s no longer allowed to pat the vagina. ‘Patting’ means if she pats with the hand, or an earthen bowl, or a brass vessel to relieve a lustful mind, she breaks a minor vinaya rule.” This is called the rule on patting with the hand.