《汉书·志·刑法志》
于是招进张汤、赵禹之辈，一条一条确定法令，制作了知人犯法不举告、负责实地监察部主有罪一同判罪的法令，放宽酷吏执法苛刻的罪过，立即诛杀放出犯人的官员。
于是招进张汤、赵禹之属，条定法令，作见知故纵、监临部主之法，缓深故之罪，急纵出之诛。
So he recruited people like Zhang Tang and Zhao Yu to set up laws and regulations step by step. They made laws punishing people who knew about crimes but did not report, punishing inspectors for not seriously inspecting, punished those releasing criminals, and killing criminals.