阿彌陀經疏 1.101

1.101

「摩訶劫賓那」者，此云房宿。相傳云：以其初入道門在僧房宿，佛知道根將熟，即自化為老比丘與之共宿，因為說法而悟聖道，故名房宿；亦名房星，因禱房星而生故以為字。

Regarding "Mahākapphiṇa": Here translated as "Chamber Lodging." Tradition states: Because when he first entered the path he lodged in a monk's chamber, the Buddha, knowing that his faculties for the path were about to ripen, transformed himself into an elderly monk to lodge together with him. Thereupon he preached the Dharma for him, and [Kapphiṇa] awakened to the holy path; hence he was called "Chamber Lodging." He was also called "Chamber Constellation," named so because he was born following a prayer to the constellation Room (Fang).