It has been reported on the authority of Anas b. Malik that the Messenger of Allah (ﷺ) used to visit Umm Haram daughter of Milhan (who was the sister of his foster-mother or his father's aunt). She was the wife of 'Ubada b. Samit, One day the Messenger of Allah (ﷺ) paid her a visit. She entertained him with food and then sat down to rub his head. The Messenger of Allah (ﷺ) dozed off and when he woke up (after a while), he was laughing. She asked:
What made you laugh. Messenger of Allah? He said: Some people from my Umma were presented to me who were fighters in the way of Allah and were sailing in this sea. (Gliding smoothly on the water), they appeared to be kings or like kings (sitting) on thrones (the narrator has a doubt about the actual expression used by the Holy Prophet). She said: Messenger of Allah, pray to Allah that He may include me among these warriors. He prayed for her. Then he placed his head (down) and dozed off (again). He woke up laughing, as before. (She said) I said: Messenger of Allah, what makes you laugh? He replied: A people from my Umma were presented to me. They were fighters in Allah's way. (He described them in the same words as he had described the first warriors.) She said: Messenger of Allah, pray to God that He may include me among these warriors. He said: You are among the first ones. Umm Haram daughter of Milhan sailed in the aea in the time of Mu'awiya. When she came out of the sea and (was going to mount a riding animal) she fell down and died.
