Umm al walad
Umm al-walad () was a title given to a slave-concubine who had given birth to her master's child.Since this concubine was the property of her master, she could be sold or given away, like any other slave. This was also the view of Muhammad. Umar had a different view: When he was caliph, he made a policy that prohibited owners from selling or gifting their umm al-walads. Also, when her owner died, the Umm-al-walad would be freed. Ali, who was Umar's cousin, and later a caliph, opposed this ruling. He said it was different from what Muhammad had said.