四分律行事鈔資持記 2.683

2.683

釋中，初科。初位十日內，雖滿不犯。若至十日得足，當日須成；不爾，十一日明出便犯。中位十九日同足即犯，後泣一日不足亦犯。得不得者，不同中位得足犯故。同不同，如後解。

Under "Explanation": the initial heading. In the initial period within ten days, even if complete, there is no offense. If upon reaching the tenth day it is made sufficient, it must be finished on that day; otherwise, when the dawn of the eleventh day arises, one immediately commits an offense. In the middle period, if matching pieces are made sufficient on the nineteenth day, one immediately commits an offense; in the final period, even if one day is insufficient, one also commits an offense. "Acquiring and not acquiring" differs because acquiring sufficiency in the middle period incurs an offense. Matching and non-matching are as explained below.