AN 3.81
Thai 3.83
Gadrabha Sutta: The Donkey
translated from the Pali by
Thanissaro Bhikkhu

"Monks, it is just as if a donkey were following right after a herd of cattle, saying, "I too am a cow! I too am a cow!" Its color is not that of a cow, its voice is not that of a cow, its hoof is not that of a cow, and yet it still keeps following right after the herd of cattle, saying, "I too am a cow! I too am a cow!" In the same way, there is the case where a certain monk follows right after the community of monks, saying, "I too am a monk! I too am a monk!" He doesn't have the other monks' desire for undertaking the training in heightened virtue, doesn't have their desire for undertaking the training in heightened mind (concentration), doesn't have their desire for undertaking the training in heightened discernment, and yet he still keeps following right after the community of monks, saying, "I too am a monk! I too am a monk!"

"So you should train yourselves: 'Strong will be our desire for undertaking the training in heightened virtue; strong will be our desire for undertaking the training in heightened mind (concentration); strong will be our desire for undertaking the training in heightened discernment.' That is how you should train yourselves."