四分律行事鈔資持記 3.1132

3.1132

《十誦》，七日。同《四分》者，據七是同。兼夜則異，《四分》日沒法謝，彼宗夜盡方失；失法雖有短長，護夏同在明相。三十九夜。眾法是同，日數則異。牒緣云是處者，即指本住處，亦同《四分》還來此中也。

The Daśādhyāya-vinaya: seven days. That it is the same as the Dharmaguptaka is based on the fact that seven is the same. When including the night, it differs: in the Dharmaguptaka the rite ceases at sunset, whereas in that school it is lost only when the night ends; although the loss of the rite differs in length, protecting the vassa is identical with the dawn sign. Thirty-nine nights: the community rite is the same, but the count of days differs. Mentioning the condition by saying "this place" refers to the original dwelling place, which also agrees with the Dharmaguptaka's "returning into this place".