[163] Now at that time a certain bhikkhu, without a waistband (kāyabandhana), entered a village for alms. His lower robe (antaravāsaka) slipped down in the street. People, seeing this, raised a jeering cry. That bhikkhu was embarrassed. Then that bhikkhu, having gone to the monastery, told this matter to the bhikkhus. The bhikkhus told this matter to the Blessed One. … "Bhikkhus, a village should not be entered without a waistband. Whoever should enter, there is an offense of wrong-doing (dukkaṭa). Bhikkhus, I allow a waistband."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.