四分律行事鈔資持記 2.1134

2.1134

三十七。（佛在羅閱城，人民節會，難陀跋難陀共看伎，并受食，而暮還耆闍山；又迦留陀夷夜入城乞食，女人電中見稱言是鬼，由此二緣故制。）

Thirty-seven. (When the Buddha was in Rājagṛha, the people held a festive gathering. Nanda and Upananda went together to watch the entertainers and also accepted food, returning to Gṛdhrakūṭa at dusk. Furthermore, Udāyin entered the city at night to beg for food, and a woman saw him in a flash of lightning and cried out that he was a ghost. On account of these two circumstances, the rule was instituted.)