四分律比丘含注戒本 1.144

1.144

佛在舍衛國。迦留陀夷聞佛已制前二戒故，便於女前，欲心向彼說麁語。比丘舉過，佛因制戒。

The Buddha was in the country of Śrāvastī. Because Kālodayin heard that the Buddha had already formulated the preceding two precepts, he then spoke lewd words in front of women with a lustful mind toward them. Bhikṣus raised the fault, and the Buddha formulated the precept on account of this.