Narrated Anas bin Malik:

Allah's Messenger (ﷺ) used to visit Um Haram bint Milhan she was the wife of 'Ubada bin As-Samit. One day the Prophet (ﷺ) visited her and she provided him with food and started looking for lice in his head. Then Allah's Messenger (ﷺ) slept and afterwards woke up smiling. Um Haram asked, "What makes you smile, O Allah's Messenger (ﷺ)?" He said, "Some of my followers were presented before me in my dream as fighters in Allah's Cause, sailing in the middle of the seas like kings on the thrones or like kings sitting on their thrones." (The narrator 'Is-haq is not sure as to which expression was correct). Um Haram added, 'I said, "O Allah's Messenger (ﷺ)! Invoke Allah, to make me one of them;" So Allah's Messenger (ﷺ) invoked Allah for her and then laid his head down (and slept). Then he woke up smiling (again). (Um Haram added): I said, "What makes you smile, O Allah's Messenger (ﷺ)?" He said, "Some people of my followers were presented before me (in a dream) as fighters in Allah's Cause." He said the same as he had said before. I said, "O Allah's Messenger (ﷺ)! Invoke Allah to make me from them." He said, "You are among the first ones." Then Um Haram sailed over the sea during the Caliphate of Muawiya bin Abu Sufyan, and she fell down from her riding animal after coming ashore, and died.