Pathikasutta 1.6.11

1.6.11

Bhavissanti kho te, sunakkhatta, vattāro, no visahi sunakkhatto licchaviputto samaṇe gotame brahmacariyaṃ carituṃ, so avisahanto sikkhaṃ paccakkhāya hīnāyāvattoti.

There will be some who say to you that Sunakkhatta was unable to lead the spiritual life under the ascetic Gotama. That’s why he resigned the training and returned to a lesser life.