釋氏稽古略 2.146

2.146

魏囚獄或積年。群臣頗言之。上皇曰。滯獄誠非善治。不猶愈於倉猝而濫乎。夫人憂苦則思善故。智者以囹圄為福堂。朕特苦之。欲其改悔而加矜恕耳（北史）。

In Northern Wei, cases of imprisonment sometimes accumulated over years, and the court officials spoke much about it. The Supreme Emperor said, "Detaining prisoners is indeed not good governance, but is it not better than being hasty and excessive? When people suffer hardship, they think of goodness; the wise regard the prison as a hall of blessing. We deliberately subject them to hardship only wanting them to reform and repent, so that We may bestow pardon on them" (History of the Northern Dynasties).