律相感通傳 1.123

1.123

「比丘食訖，還僧坊中，以事白佛。由此佛制，還以衣角居于左臂，坐具還在衣下。

"After the monks finished eating, they returned to the monastery and reported the matter to the Buddha. Because of this, the Buddha regulated that the corner of the robe should once again rest on the left arm, and the sitting mat should once again be beneath the robe.