Ibn Jurayj (may Allah have mercy on him) says: I said to Ata' (may Allah have mercy on him): I made a contract of manumission (mukatabah) with two men in a sale on the condition: "The living one of you is responsible for the dead one of you, and the wealthy one of you for the destitute one of you." He said: This is permissible. This is also the view of Amr bin Dinar (may Allah have mercy on him) and Sulayman bin Musa (may Allah have mercy on him), and he said: It is za'amah, meaning hamalah (suretyship).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب المكاتب / 21633
Ibn Jurayj (may Allah have mercy on him) says: I said to Ata' (may Allah have mercy on him): I made a contract of manumission (mukatabah) with two slaves of mine and wrote that (each is liable for the other) upon them. He said: It is not permissible with your two slaves. Sulayman bin Musa also said the same. Ibn Jurayj says: I said to Ata': Why is it not permissible? He said: Because if one of them becomes bankrupt, he returns to being a slave who owns nothing of yours.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب المكاتب / 21634
Qatadah and Ata' (may Allah have mercy on them both) say regarding a man who makes a contract of manumission (mukatabah) with two slaves together on the condition that the living one of you is responsible for the dead one of you, and the destitute one of you is the responsibility of the wealthy one of you: They both said: This is not permissible.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب المكاتب / 21635