Musannaf Ibn Abi Shaybah

It is narrated from Hazrat Abu Bakr bin Amr bin Hazm that a man made his slave a mukatab (contracted for freedom), and set the condition that the payment for the contract of freedom would be made in installments. The mukatab brought the entire payment for the contract of freedom at once, but his master refused to accept the whole amount together. The mukatab then presented himself before Hazrat Umar, who summoned his master. When he came, Hazrat Umar presented the entire amount to him, but he refused to accept it. Hazrat Umar said, "O Yarfa! Place this money in the treasury (Bait-ul-Mal), and let the master receive it from the treasury in installments." And to the slave he said, "Go, you are free."