Umar bin Khattab reported,

Umar reported that when the captives had been taken, the Messenger of Allah ﷺ asked Abu Bakr and Umar, "What do you think should be done with these captives?"Abu Bakr said, "Prophet of Allah, they are our cousins and kin. I think you should accept a ransom from them, so that it may give us strength against the disbelievers, and perhaps Allah will guide them to Islam."The Messenger of Allah ﷺ then asked, "And what do you think, son of Khattab?"Umar said, "I said, 'No, by Allah, Messenger of Allah, I do not hold the view that Abu Bakr holds. I think you should hand them over to us so we may strike off their necks. Hand Aqeel over to Ali, and let him strike off his neck, and hand so-and-so over to me,' naming a relative of his, 'and let me strike off his neck. These men are the leaders of disbelief and its chieftains.'"The Messenger of Allah ﷺ favored what Abu Bakr had said and did not favor what Umar said.Umar continued, "The next day I came, and there were the Messenger of Allah ﷺ and Abu Bakr sitting and weeping. I said, 'Messenger of Allah, tell me what has made you and your companion weep. If I find cause to weep, I will weep, and if I find no cause to weep, I will force myself to weep along with you.'The Messenger of Allah ﷺ said, 'I am weeping over what was presented to me concerning your companions taking the ransom. Their punishment was shown to me as near as that tree,'" a tree close to the Prophet of Allah ﷺ.Then Allah revealed, "It is not for a prophet to have captives until he has thoroughly subdued the land" [Anfal 8:67] up to His words, "So eat of what you have gained of war booty, lawful and good" [Anfal 8:69]. So Allah made the spoils lawful for them.

عن عمر بن الخطاب قال

فلما أسروا الأسارى، قال رسول الله ﷺ لأبي بكر وعمرما ترون فى هؤلاء الأسارى؟ فقال أبو بكر: يا نبي الله! هم بنو العم والعشيرة، أرى أن تأخذ منهم فدية، فتكون لنا قوة على الكفار، فعسى الله أن يهديهم للإسلام. فقال رسول الله ﷺ: ما ترى يا ابن الخطاب. قلت: لا والله يا رسول الله! ما أرى الذي رأى أبو بكر، ولكني أرى أن تمكنا فنضرب أعناقهم، فتمكن عليا من عقيل، فيضرب عنقه، وتمكنى من فلان (نسيبا لعمر)، فأضرب عنقه فإن هؤلاء أئمة الكفر وصناديدها، فهوي رسول الله ﷺ ما قال أبو بكر، ولم يهو ما قلت، فلما كان من الغد جئت، فإذا رسول الله ﷺ وأبو بكر قاعدين يبكيان، قلت: يا رسول الله! أخبرني من أي شيء تبكي أنت وصاحبك؟ فإن وجدت بكاء بكيت، وإن لم أجد بكاء تباكيت لبكائكما. فقال رسول الله ﷺ: أبكي للذي عرض على أصحابك من أخذهم الفداء، لقد عرض علي عذابهم أدنى من هذه الشجرة شجرة قريبة من نبي الله ﷺ و أنزل الله عز وجل {ما كان لنبي أن يكون له أسرى حتى يثخن في الأرض} إلى قوله {فكلوا مما غنمتم حللا طيبا} فأحل الله الغنيمة لهم.