諸經要集 20.55

20.55

又僧祇律云。佛言。若急下風來當制。若不可忍者。當向下坐。不得在前縱氣。若氣來不可忍者。當下道在下風放之。

Also, the Mahāsāṃghika-vinaya states: “The Buddha said: ‘If urgent downward wind comes, one should restrain it. If it cannot be suppressed, one should face downward; one must not release gas in front [of others]. If gas comes and cannot be suppressed, one should step down from the path and release it downwind.’”