Before joining the order, he was part of the Royal barber caste and worked as a barber. When he cut the Buddha's hair, the Buddha told Upali that he was breathing too fast. So, he learned how to control his mind by controlling his breathing. Later, he asked the Buddha if a person of "low birth" such as he could join the order. The Buddha ordained him before the princes and asked the princes to pay homage to Upali, who had by then become an Arhant and was an elder compared with the seven princes. He became the chief disciple in knowing the rules of the order and the foremost disciple in keeping precepts, later developing the Vinaya.
- "Upali". What-Buddha-Said.net. Retrieved 2017-09-28.
- "Buddhist Studies: Disciples of the Buddha: Upali (Student version)". buddhanet.net. Retrieved 2017-09-28.
- "Upāli". palikanon.com. Retrieved 2017-09-28.