大比丘三千威儀 2.18

2.18

There are three matters for which [a śrāmaṇera] should be expelled: First, saying that violating the precepts incurs no fault; second, saying that the Buddha, Dharma, and Saṅgha do not exist; third, going around telling others of the good and bad deeds of his upādhyāya or ācārya.