律戒本疏 1.36

1.36

十五尼師檀　是坐具也。諸比丘多畜地敷及坐具。新故相積盈滿。移枷眾僧受請。世尊往後開一房行。視見之人謙曰。受而不用無益於施主。又多欲妨學非沙門法。因是結戒。令用故緣之。施者得福。受者無罪。若有故縟純新作者捨墮。若無故縟純新無罪。

Fifteenth: Niṣīdana. This is the sitting mat. Various monks stored many ground spreads and sitting mats; the new and old accumulated until overflowing. Moving to the Sangha's quarters, they accepted invitations. The World-Honoured One subsequently went and opened one room to inspect it; people who saw it complained, saying: "Receiving without using brings no benefit to the donors. Moreover, having many desires hinders learning and is not the Dharma of a śramaṇa." On this account, the precept was formulated: he ordered them to use the old to border it, so that the donor obtains merit and the recipient is without offense. If one has an old mattress and makes one entirely of new material, it is a niḥsargika-pāyattika; if one has no old mattress, making one of entirely new material is without offense.