法苑珠林 88.8

88.8

夫欲受戒者。戒師先須問其遮難。故成實論問遮。逆罪人賊住。污比丘尼等不聽作比丘。是等諸人若為白衣得善律儀。不遮修行施慈等善。但有世間戒。以是人為業所污亦障聖道故。不聽出家。

Whoever wishes to receive the precepts must first be questioned by the preceptor regarding impediments and obstacles. Therefore, the Tattvasiddhi-śāstra inquires into impediments: perpetrators of unpardonable sins, those who dwell as thieves [in the Saṅgha], and those who defile bhikṣuṇīs are not permitted to become bhikṣus. If such persons become white-robed laity, they attain wholesome moral restraint, and are not impeded from cultivating wholesome deeds such as giving and loving-kindness; they only possess mundane precepts. Because these persons are defiled by their karmic actions and also obstructed from the noble path, they are not permitted to leave the household life.