Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates that it had been made obligatory upon the Muslims that one man should fight ten men. This command weighed heavily upon them and was hard for them, so Allah Almighty lightened it for them, and the command became that one man should fight two men. Concerning this, Allah Almighty revealed these verses: "If there are twenty among you who are steadfast, they will overcome two hundred," to the end of the verses. Then He said: "Had it not been for a decree from Allah that preceded, a great punishment would have touched you for what (ransom) you took." That is, Allah Almighty says: "Had it not been that I do not punish anyone who disobeys Me until I have warned him beforehand (the punishment would have reached you)." Then He said: "O Prophet, say to those captives who are in your hands," to the end of the verse. At this, Sayyiduna al-Abbas (may Allah be pleased with him) said: "By Allah! This verse was revealed about me, when I informed the Messenger of Allah (peace and blessings be upon him) of my Islam and asked him to count the twenty uqiyah (of gold) which I had brought with me to my account (as ransom). So in exchange for it he (peace and blessings be upon him) gave me twenty slaves, each of whom trades with my wealth that is in his hands, and along with that I hope for the forgiveness of Allah, exalted be His mention."
Imam al-Tabarani (may Allah have mercy on him) said: "This hadith, in this complete form, was narrated from Muhammad bin Ishaq only by Jarir bin Hazim, and Wahb bin Jarir is alone in narrating it."
Hadith Referenceالمعجم الأوسط / باب الميم / 8107
Hadith Takhrij«أخرجه البخاري فى «صحيحه» برقم: 4652، 4653، وابن الجارود فى «المنتقى» برقم: 1125، وابن حبان فى «صحيحه» برقم: 4773، والضياء المقدسي فى «الأحاديث المختارة» برقم: 488، 489، 214، 215، 212، 213، وأبو داود فى «سننه» برقم: 2646، وسعيد بن منصور فى «سننه» برقم: 1000، 2537، والبيهقي فى «السنن الكبرى» برقم: 18156، 18155، وابن حجر فى «المطالب العالية» برقم: 4248، وعبد الرزاق فى «مصنفه» برقم: 9525، والطبراني فى «الكبير» برقم: 11211، 11396، 11397، 11398، والطبراني فى «الأوسط» برقم: 7804»