四分律行事鈔資持記 3.277

3.277

可不中，初正明。五下，引示，《五分》。與究竟者，由存始終，即行滿故。《僧祇》中，初簡不合。自樂福者，非益他故。邪命為衣食故。若下，次明合賞。

Under 'Permissible or not', first, it explains directly. The phrase 'Five under...' cites the Mahīśāsaka-vinaya to illustrate: giving to one who stayed until the conclusion is because he maintained it from beginning to end, meaning his practice was complete. In the Mahāsāṃghika-vinaya, first, it screens out those who do not qualify: one who delights in merit for oneself does not benefit others; wrong livelihood is for clothing and food. The phrase 'If under...' next explains those who qualify for reward.