At one time when the Buddha was staying in the Sakyan country in the Banyan Tree Monastery at Kapilavatthu, the monks from the group of six went to the nunnery and instructed the nuns from the group of six. Soon afterwards, other nuns said to the nuns from the group of six, “Come, venerables, let’s go to the instruction.” “There’s no need. The monks from the group of six came and instructed us right here.” The nuns complained and criticized the monks from the group of six, “How could the monks from the group of six go to the nunnery and instruct the nuns?” Then those nuns told the monks. The monks of few desires complained and criticized those monks, “How could those monks do this?”… “Is it true, monks, that you did this?” “It’s true, sir.” The Buddha rebuked them … “Foolish men, how could you do this? This will affect people’s confidence …” … “And, monks, this training rule should be recited like this:

Preliminary ruling ‘If a monk goes to a nunnery and instructs the nuns, he commits an offense entailing confession.’”