This episode is a narration of the 47th Sutta of the Middle Discourses of the Buddha, The Vīmaṁsaka Sutta, which translates as “The Inquirer”. While some spiritual teachers prefer to remain in obscurity, the Buddha not only encouraged his followers to closely investigate him, but gave them a detailed and demanding method to do so.
This translation of the Vīmaṁsaka Sutta is by Bhikkhu Sujato and was sourced from Sutta Central.