It is narrated from Hazrat Abu Umamah (may Allah be pleased with him) that when the Noble Prophet (peace and blessings be upon him) returned from Khaybar, he had two slaves with him. The Noble Prophet (peace and blessings be upon him) gave one of the slaves to Hazrat Ali (may Allah be pleased with him) and said, "Do not beat him, because I have forbidden beating those who pray, and I have seen him praying." The other slave was given to Hazrat Abu Dharr (may Allah be pleased with him), and he said, "I advise you to treat him well." So he set him free. One day, the Noble Prophet (peace and blessings be upon him) asked him, "What happened to that slave?" He replied, "O Messenger of Allah! You advised me to treat him well, so I set him free."