四分律比丘含注戒本 3.317

3.317

佛在舍衛。六群宿佛塔中，有慚愧比丘舉過白佛，因而訶制。

The Buddha was in Śrāvastī. The group of six lodged overnight in a Buddha stūpa. Bhikṣus with a sense of shame reported the fault to the Buddha, who thereupon rebuked them and formulated [the precept].