Regarding slaves, when Muhammad (peace and blessings of Allah be upon him) became the messenger of Allah, the people of his land had become accustomed to having countless slaves and usually treated them quite harshly. During the period of his prophethood he worked diligently to do what he could to cut down on their numbers. Islam closed most of the doors leading to slavery and encouraged the freeing of slaves in many ways. He constantly exhorted those who owned slaves to treat them kindly and well. He insisted that they must treat the slaves fairly and with mercy. The Holy Prophet (peace and blessings of Allah be upon him) says:
If the owner of a slave beat his slave or abused him, the only compensation that he could make was to set the slave free. (Sahih Muslim)
The Holy Prophet (peace and blessings of Allah be upon him) always devised and encouraged his followers for freeing of slaves on every pretext. He said:
If a person owning a slave sets him free, God will in recompense save every part of his body corresponding to every part of the slave’s body from the torment of Hell. (Sahih Muslim)
Again, he laid down that a slave should be asked to perform only such tasks as he could easily accomplish and that when he was set to do a task, his master should help him in performing it so that the slave should experience no feeling of humiliation or degradation.
If a master went on a journey accompanied by a slave, it was his duty to share his mount with the slave either by both riding together or each riding in turn.
Abu Huraira after becoming a Muslim spent the whole of his time in the company of the Prophet (peace and blessings of Allah be upon him) and he had repeatedly heard the Prophet’s injunctions regarding the treatment of slaves, has said:
I call God to witness in Whose hands is my life that were it not for the opportunities that I get of joining in holy war and of performing the Pilgrimage and were it not that I have opportunities of serving my old mother, I would have desired to die a slave, for the Holy Prophet (peace and blessings of Allah be upon him) constantly insisted upon slaves being well and kindly treated. (Sahih Muslim)
Abu Dharr, a companion of the Holy Prophet (peace and blessings of Allah be upon him), narrated about the advices given by the Holy Prophet (peace and blessings of Allah be upon him) regarding the slaves in the following words:
The Prophet (peace and blessings of Allah be upon him) said: ‘Feed those of your slaves who please you from what you yourselves eat and clothe them with what you clothe yourselves, but sell those who do not please you and do not punish Allah’s creatures. (Abu Dawud)
It was not just a lip service on the part of the Holy Prophet (peace and blessings of Allah be upon him). He himself was an excellent exemplar for his followers in the kind treatment of the slaves. The Holy Prophet (peace and blessings of Allah be upon him) set a good example of kindness, which created a constructive effect upon his people. His wife Khadijah had made him a present of a young slave named Zaid Ibn Harith, who had been brought as a captive to Mecca and sold to Khadijah. When Zaid’s father heard that Muhammad (peace and blessings of Allah be upon him) possessed Zaid, he came to Mecca and offered a large sum for his ransom. Whereupon Muhammad (peace and blessings of Allah be upon him) said, “Let Zaid come here, and if he chooses to go with you, take him without ransom; but if it be his choice to stay with me, why should I not keep him?” Harith agreed to this proposal of the Holy Prophet (peace and blessings of Allah be upon him). He had no doubt that his son would not make a decision other than to go with him. The father did not know that Prophet of Islam had given him love more than the parents, and that his son would give preference to the Holy Prophet (peace and blessings of Allah be upon him) over his parents. Zaid, being brought into the presence of the Holy Prophet (peace and blessings of Allah be upon him), declared that he would stay with his master, who treated him as if he were his only son. Muhammad (peace and blessings of Allah be upon him) no sooner heard this than he took Zaid by the hand and led him to the black stone of Kaaba, where he publicly adopted him as his son, to which the father acquiesced and returned home well satisfied. Henceforward Zaid was called the son of Muhammad (peace and blessings of Allah be upon him).
Marur bin Suwaid relates: “I saw Abu Dharr Ghaffari, the Companion of the Holy Prophet (peace and blessings of Allah be upon him), wearing clothes exactly similar to those worn by his slave. I inquired of him the reason for this and he said:
During the lifetime of the Holy Prophet (peace and blessings of Allah be upon him) I once taunted a man with his mother having been a slave. Upon this the Holy Prophet (peace and blessings of Allah be upon him) rebuked me and said: “You still seem to entertain pre-Islamic notions. What are slaves? They are your brethren and a source of your power. God in His wisdom confers temporary authority upon you over them. He who has such authority over his brother should feed him with the kind of food he himself eats; clothe him with the kind of clothes he himself wears and should not set him a task beyond his strength and should himself help him in whatever he is asked to do.” On another occasion the Prophet said: “When your servant cooks food for you and sets it out before you, you should ask him to sit down with you to eat or at least to partake of a portion of it in your company, for he has established a right in it by working on it.” (Sahih Muslim)
Abu Masud Al-Ansari was a companion of the Holy Prophet (peace and blessings of Allah be upon him), he once beat his slave, and Holy Prophet (peace and blessings of Allah be upon him) admonished him in the following words, which are narrated by Abu Masud himself. He said: I was beating my slave with a whip when I heard a voice behind me, “Understand Abu Masud,” but I did not recognize the voice due to intense anger. He (Abu Masud) reported: As he came near me, I found that he was the Messenger of Allah (peace and blessings of Allah be upon him) and he was saying, “Bear in mind, Abu Masud. Bear in mind, Abu Masud.” He (Abu Masud) said, I threw the whip from my hand. Thereupon he (the Prophet, peace and blessings of Allah be upon him) said, “Bear in mind, Abu Masud, verily Allah has more dominance upon you than you have upon your slave. I then said, I would never beat my servant in future. (Sahih Muslim)
Abdullah ibn ‘Umar talks about forgiveness of the slaves as he heard from the Holy Prophet (peace and blessings of Allah be upon him) of Islam:
An A‘rabi (desert Arab) came to the Prophet of Allah (peace and blessings of Allah be upon him) and said, O Messenger of Allah, how many times should I forgive my slave every day? The Prophet (peace and blessings of Allah be upon him) replied: Seventy times. (Tirmidhi and Abu Dawud)