It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) accepted ransom for the captives of Badr, and the ransom of each of them was four thousand (dirhams). He (peace and blessings be upon him) had Uqbah bin Abi Mu'ayt killed before (the matter of) the ransom; Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) went up to him and killed him while he was a bound captive. He (Uqbah) said: "O Muhammad (peace and blessings be upon him)! Who will there be for the children?" He (peace and blessings be upon him) said: "The Fire."
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from Uthman al-Jazari except Ma'mar."
Hadith Referenceالمعجم الأوسط / باب الألف / 3003
Hadith Takhrij«أخرجه عبد الرزاق فى «مصنفه» برقم: 9394، والطبراني فى «الكبير» برقم: 12154»