Imam Ahmad recorded that Anas said, "The Prophet asked the people for their opinion about the prisoners of war of Badr, saying,

«إِنَّ اللهَ قَدْ أَمْكَنَكُمْ مِنْهُم»

(Allah has made you prevail above them.) `Umar bin Al-Khattab stood up and said, `O Allah's Messenger! Cut off their necks,' but the Prophet turned away from him. The Messenger of Allah ﷺ again asked,

The second verse (68) is also a supplement to this admonition where it has been said that had it not been for a Divine writ already established, the course of action which you opted for - that of releasing the prisoners against ransom - would have brought upon you some grave punishment.

What is this writ and what does it mean? According to a narration from Sayyidna Abu Hurairah ؓ reported in Tirmidhi, the Holy Prophet ﷺ said: Spoils were not lawful for any community before you. When, on the occasion of Badr, Muslims went after collecting spoils - though, spoils were not made lawful for them until that time - this verse was revealed. It emphasized that this initiative taken by Muslims, before the injunction making spoils lawful for them was revealed, was a sin which deserved instant punishment. But, since the writ of Allah that spoils shall be made lawful for this community was already there in the Preserved Tablet, therefore, punishment was not sent over Muslims for this misconduct. (Mazhari)