In the battle of Badr, which was the first confrontation between Islam and its enemies, 70 polytheists were killed, 70 more taken prisoners and 13 Muslims were killed.

The Prophet Mohammad returned to Madina with the booty of the polytheists and the 70 prisoners of war. He decided to seek advice from Abu Bakr concerning these prisoners and asked him:

- "What do you think about it, oh Abu Bakr?"

He answered: "They are your people, the sons of your maternal uncle. If you kill them, they will enter the Fire; but if you let them free for a ransom, Allah will cause them to accept islam and what you would take for them (as ransom) would be a strengthening of the muslim and an additional support in their struggle against their foes."

Then the Messenger of Allah ﷺ turned to Omar and asked him:

- "What is your opinion, oh Abu Hafs?"

He answered; "You have now in front of you the leaders of the polytheists and their heroes, so cut of their necks and God will not be lacking in His bounties and power to the muslims."
It was on this occasion that the Messenger of Allah ﷺ while turning to Abu Bakr, remarked the following:

- "Your example (mathalu-ka, your spiritual type) among the angels, oh Abu Bakr, is the archangel Michael - peace be upon him, as he descends to the earth only with compassion (al-rahmah). And your spiritual type among the prophets is Abaraham (peace be upon him), who said the following words, according to the quranic verse:

... Then whoever follows me, he is surely of me, and whoever disobeys me, Thou surely arc Forgiving, Merciful.
Qurān 14, 36

But your spiritual type (a) is also Jesus' (peace be upon him) when he exclaimed according to the quranic verse:

If Thou shouldst chastise them, then surely they are Thy
servants; and if Thou shouldst forgive them, then surely Thou
art the Mighty, the Wise.
Qurān 5, 188

Then the Prophet ﷺ turned to Omar and told him:
Your example (mathalu-ka, your spiritual type) among the angels, oh Omar, is Gabriel (peace upon him), because he descends with punishment and sternness (bi al-'adhābi wa al-shiddah). And your spiritual type among the prophets is Noah (peace be upon him), when he cried:

... My Lord! leave not upon the land any dweller from among the unbelievers.
Qurān 71,26

You also have the spiritual type of Moses (peace be upon him) when he exclaimed against Pharao and his people:

... Our Lord! destroy their riches and harden their hearts so that they believe not until they see the painful punishment.
Qurān 10,88

In the meantime the question of the booty and the prisoners was still unsolved. After seeking the advice of his two companions about the fate of the prisoners, the Messenger ﷺ tended toward the opinion of Abu Bakr, which was to set them free for a ransom. In the morning however, when Omar visited the Messenger of Allah ﷺ , he found him with Abu Bakr crying. Omar asked:
Oh Allah's Messenger, why are you weeping?"
He answered: "I am weeping because of what has occurred to your companions concerning the ransom". Meaning because of the revelation of the following verses:

It is not fit for a prophet that he should take captives unless he has fought and triumphed in the land; you desire the frail goods of this world, while Allah desires (for you) the hereafter; and Allah is Mighty, Wise.
Were it not for an ordinance from Allah that had already gone forth, surely there would have befallen you a great chastisement for what you had taken to.
Qurān 8, 67-68

It is also reported that the Prophet ﷺ once exclaimed:
"If once a punishment is sent down from Heaven, none would escape except for Omar, for he was the only one, who did not slacken from the struggle (lam yatruk al-qitāl)".

But it was not really because of the question of the booty, why doubts and opposition emerged, instead the problem of the prisoners was to be solved before the war had ended, as proven by the above two quranic verses:

Eat then of the lawful and good (things) which you have acquired in war, and be careful of (your duty to) Allah; surely Allah is Forgiving, Merciful.
Qurān 8,69

For Allah speaks the truth and He alone guides to the right way.