Umm Haraam and Umm Sulaym were mahrams of the Prophet (peace and blessings of Allaah be upon him)

Umm Sulaym’s full name was Sahlah or Rumaylah or Mulaykah bint Milhaan ibn Khaalid ibn Zayd ibn Haraam ibn Jundub al-Ansaariyyah (may Allaah be pleased with her). She was the mother of Anas ibn Maalik (may Allaah be pleased with him), and is best known by her kunyah; there is some difference of opinion as to her given name. Al-Isaabah, 8/227. 

Umm Haraam was the daughter of Milhaan (may Allaah be pleased with him), and was the sister of Umm Sulaym. Ibn ‘Abd al-Barr said: I could not find out her real name.  

They were both mahrams of the Prophet (peace and blessings of Allaah be upon him). 

Al-Bukhaari (2789) and Muslim (1912) narrated from Anas ibn Maalik (may Allaah be pleased with him) that he heard him say that the Messenger of Allaah (peace and blessings of Allaah be upon him) used to enter upon Umm Haraam bint Milhaan and she would give him food. Umm Haraam was married to ‘Ubaadah ibn al-Saamit. One day the Messenger of Allaah (peace and blessings of Allaah be upon him) entered upon her, and she provided him with food and started grooming his head. Then the Messenger of Allaah (peace and blessings of Allaah be upon him) slept, then he woke up smiling. Umm Haraam asked, “What makes you smile, O Messenger of Allaah?” He said, “Some people of my ummah were shown to me (in my dream) fighting for the sake of Allaah, sailing in the middle of the seas like kings on the thrones or like kings sitting on their thrones.” (The narrator Ishaq is not sure as to which expression was correct). Umm Haraam added, “I said, ‘O Messenger of Allaah! Pray to Allaah to make me one of them.’ ” So the Messenger of Allaah (peace and blessings of Allaah be upon him) prayed to Allaah for her and then laid his head down (and slept). Then he woke up smiling (again). (Umm Haraam added): I said, “What makes you smile, O Messenger of Allaah?” He said, “Some people of my ummah were shown to me (in my dream) fighting for the sake of Allaah.” He said the same as he had said before. I said, “O Messenger of Allaah! Pray to Allaah to make me one of them.” He said, “You will be among the first ones.” Then Umm Haraam sailed across the sea during the Caliphate of Mu’aawiya ibn Abi Sufyaan, and she fell down from her riding animal after coming ashore, and died. 

Muslim (2331) narrated that Anas ibn Maalik said: The Prophet (peace and blessings of Allaah be upon him) used to enter Umm Sulaym’s house and sleep on her mattress when she was not there. He came one day and slept on her mattress, then someone went to her and said to her, “The Prophet (peace and blessings of Allaah be upon him) is sleeping in your house on your bed.” She came and saw that he had sweated and his sweat had soaked a piece of cloth that was on the mattress. She opened her box and started collecting that sweat and squeezing it into bottles. The Prophet (peace and blessings of Allaah be upon him) woke with a start and said, “What are you doing, O Umm Sulaym?” She said, “O Messenger of Allaah, we hope for the barakah (blessing) of this sweat for our children.” He said, “You are right.” 

Al-Nawawi (may Allaah have mercy on him) said: 

“The scholars are agreed that Umm Haraam was a mahram of the Prophet (peace and blessings of Allaah be upon him), but they differed as to how that came about. Ibn ‘Abd al-Barr and others said that she was one of his maternal aunts through radaa’ah (breastfeeding). Others said that she was the maternal aunt of his father or his grandfather, because ‘Abd al-Muttalib’s mother was from Banu al-Najjaar.” 

He also said: 

“Umm Haraam was the sister of Umm Sulaym, and they were maternal aunts of the Messenger of Allaah (peace and blessings of Allaah be upon him) and his mahrams, either through radaa’ah or through blood. So it was permissible for him to be alone with them and to enter upon them on his own, but he did not enter upon any other woman apart from his wives.