佛祖統紀 37.49

37.49

永定元年詔迎佛牙於杜姥宅（姥莫補反老婦之稱）設四部無遮大會（比丘等四眾名為四部）。

In the first year of the Yongding era, an edict ordered the reception of the Buddha's tooth relic from the house of Old Lady Du (姥 [mǔ], pronounced mo-bu reversed, an appellation for an old woman), and an unhindered great assembly of the fourfold community was held (the four assemblies of bhikṣus and so forth are called the fourfold community).