四分律比丘含注戒本 2.463

2.463

若夜、藥有分齊，夏四月應受。若夜無分齊，隨施時應受，不論藥分齊也。

(If there are set limits for the nights and for the medicine, he should accept for the four months of the summer [vassa]. If there is no set limit for the nights, he should accept according to the time of donation, regardless of the limit on the medicine.)