Habib bin Abi Thabit said that Sayyiduna Uthman (may Allah be pleased with him) used to say that the captive is to be made an heir only on the basis of proof.
These chains from Umar and Uthman (may Allah be pleased with them both) are all weak.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18340