四分律行事鈔資持記 2.2133

2.2133

明入捨中，初列輕物入捨。佛所開物，犯者數故。若下，次明重物不入。由佛不聽，為之稀故。

Under explaining entering relinquishment: First, listing light items that enter relinquishment: because they are things permitted by the Buddha, violators are frequent. From 'If' onward, next explaining that heavy items do not enter: because the Buddha did not allow them, doing so is rare.