سنن النسائي

It was narrated from An-Nu'man bin Bashir that: a group of the Kala'iyin complaned to him about some people who had stolen some goods, shoe detained them for several days, and then he let them go. They came and said: "You let them go without any pressure (to make them admit to their crime) or beating?" An-Nu'man said: "What do you want? If you wish, I will beat them, and if Allah brings back your goods thereby, all well and good. Otherwise I will take retaliation from your backs (by beating you) likewise." They said: "is this your ruling?" He said: "This is the ruling of Allah and His Messenger "(Daif)