四分律比丘含注戒本 2.3

2.3

The Buddha was in Śākyavartin. The Śākya Hastikāśyapa was adept at debate; when he was getting the worst of a debate with non-Buddhists, he went back on his previous words; if questioned in the Saṃgha, he also contradicted his words. The brahmins ridiculed them, saying there was no True Dharma, and bhikṣus reported the fault to the Buddha. On this occasion, he laid down this precept.