大方便佛報恩經 6.88

6.88

憂波離復白佛言：「若受具戒，一時得三種戒者，何須次第先受五戒，次受十戒，後受具戒耶？」

Upāli further said to the Buddha, “If by receiving the complete precepts one obtains all three kinds of precepts all at once, why is it necessary to receive them sequentially, first receiving the five precepts, next receiving the ten precepts, and later receiving the complete precepts?”