佛說觀佛三昧海經 3.45

3.45

They immediately went to the Buddha's place and said: "Bhagavat! We wish to go forth into homelessness." The Buddha said to the Śākya sons: "Welcome, monks!" Their beards and hair naturally fell away, and they instantly became śramaṇas; the clothes they wore transformed into Dharma robes. They joined their palms, paid homage to the Buddha, and recited 'Homage to the Buddha.' Before they could even lift their heads, they became arhats, fully endowed with the three knowledges and six supernormal knowledges.