No he made it a act of piety to free slaves. He was also the first to insist that they have rights as human beings. Which is why it is rare to find anyone today who has negative emotions from being the descendent of a slave anywhere in the Middle East.
* 4:36 "(Show) kindness unto parents, and unto near kindred, and orphans, and the needy, and unto the neighbour who is of kin (unto you) and the neighbour who is not of kin, and the fellow-traveller and the wayfarer and (the slaves) whom your right hands possess."
* 4:92 "It is not for a believer to kill a believer unless (it be) by mistake. He who hath killed a believer by mistake must set free a believing slave, and pay the blood- money to the family of the slain, unless they remit it as a charity. If he (the victim) be of a people hostile unto you, and he is a believer, then (the penance is) to set free a believing slave."
* 23:5-6 "And who guard their modesty - Save from their wives or the (slaves) that their right hands possess."
* 24:31 "And tell the believing women to lower their gaze and be modest, and to display of their adornment only that which is apparent, and to draw their veils over their bosoms, and not to reveal their adornment save to their own husbands or fathers or husbands' fathers, or their sons or their husbands' sons, or their brothers or their brothers' sons or sisters' sons, or their women, or their slaves."
* 24:58 "O ye who believe! Let your slaves, and those of you who have not come to puberty, ask leave of you at three times (before they come into your presence)."
* 33:25-26 "Allah repulsed the disbelievers in their wrath; they gained no good. Allah averted their attack from the believers. Allah is ever Strong, Mighty. And He brought those of the People of the Scripture who supported them down from their strongholds, and cast panic into their hearts. Some ye slew, and ye made captive some.
* 33:50 "O Prophet! Lo! We have made lawful unto thee thy wives unto whom thou hast paid their dowries, and those whom thy right hand possesseth of those whom Allah hath given thee as spoils of war."
* 33:55 "It is no sin for them (thy wives) to converse freely) with their fathers, or their sons, or their brothers, or their brothers' sons, or the sons of their sisters or of their own women, or their slaves."