In a harem, a man's one or more wives, concubines, and slave girls reside. The harem quarters for the Prophet's wives and kept women were (( Sahih Muslim, Islamic Foundation, Hadith: 6766 )) (( Sahih Muslim, Islamic Foundation, Volume 6, Page 285 )) -

Sahih Muslim (IF)
Chapter: 51 / Repentance
Section: 11. The harem of the Messenger of Allah (ﷺ) being cleared of suspicion
6766. Narrated by Zuhayr ibn Harb (RA) … from Anas (RA). He said, an accusation (slander) was brought against a man with the umm walad of the Messenger of Allah (peace be upon him) . Then the Messenger of Allah (peace be upon him) said to Ali (RA), "Go. Cut off his head." Ali (RA) went to him and found him cooling his body in a well. Ali (RA) said to him, "Come out." He reached his hand out toward Ali (RA). He pulled him out and saw that his male organ had been severed — he had no penis. Then Ali (RA) refrained from killing him. After that, he came to the Prophet (peace be upon him) and said, "O Messenger of Allah! His penis has been cut off; he has no penis."
Hadith grade: Sahih (Authentic)