It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that there was a black woman who used to sweep the mosque. She passed away (and the Companions buried her). When the Messenger of Allah (peace and blessings of Allah be upon him) did not see her, after a few days he inquired about her. He was informed that she had passed away. The Messenger of Allah (peace and blessings of Allah be upon him) said: "Why did you not inform me?" Then he (peace and blessings of Allah be upon him) went to her grave and offered her funeral prayer.