The Koran's injunctions on looted property which includes women and children and those men that for some reason or other were not killed in raids and were taken as captives. Such men, women and children were classed as slaves. The slaves were merchandise that could be sold, maltreated or killed without compunction with or without valid reason, by the believer.

LIX/5-6:
Whatsoever palm-trees ye cut down or left standing on their roots, it was by Allah's leave, in order that He night confound the evil-livers. And that which Allah gave as spoil unto His messenger from them, ye urged not any horse or riding-camel for the sake thereof, but Allah giveth His messenger lordship over whom He will. Allah is Able to do all things.

XLIX/20-21:
Allah promiseth you much booty that ye will capture, and bath given you this in advance, and bath withheld men's hands from you, that it may be a taken for the believers, and that He may guide you on a right path. And other (gain), which ye have not been able to achieve, Allah will compass it. Allah is Able to do all things.

VIII/41:
And know that whatever ye take as spoils of war, lo! a fifth thereof is for Allah, and for the messenger and for the kinsman (who bath need) and orphans and the needy and the wayfarer, if ye believe in Allah and that which We revealed unto Our slave on the Day of Discrimination, the day when the two armies met. And Allah is Able to do all things.

VIII/65:
O Prophet! Exhort the believers to fight. If there be of you twenty stedfast they shall overcome two hundred, and if there be of you a hundred stedfast they shall overcome a thousand of those who disbelieve, because they (the disbelievers) are a folk without intelligence.

VIII/67-69:
It is not for any Prophet to have captives until he bath made slaughter in the land. Ye desire the lure of this world and Allah desireth (for you) the Hereafter, and Allah is Mighty, Wise. Had it not been for an ordinance of Allah which had gone before, an awful doom had come upon you on account of what ye took. Now enjoy what ye have won, as lawful and good, and keep your duty to Allah. Lo! Allah is Forgiving, Merciful.

VIII/73:
And those who disbelieve are protectors one of another. - If ye do not so, there will be confusion in the land, and great corruption.

Footnotes

1.  vv. 67-69 were revealed when the Prophet had decided to spare the lives of the prisoners taken at Badr and hold them to ranson, against the wish of Umar, who would have executed them for their past crimes. The Prophet took the verses as a reproof, and they are generally understood to mean that no quarter ought to    have been given in that first battle.