‏الأيمان : Hadeeth No:4100 Abu Huraira reported Allaah's Messenger (sallAllaahu alayhi wa sallam) as saying: When a slave fulfils obligation of Allaah and obligation of his master, he has two rewards for him. I narrated this to Ka'b, and Ka'b said: (Such a slave) has no accountability, nor has a poor believer....

‏البيوع : Hadeeth No:3743 Rafi b. Khadij (Allaah be pleased with him) reported: We used to give land on rent, and we rented it on one-third or one-fourth share. The rest of the hadith is the same....