'Ali ibn Abi Talib was the cousin of the Messenger of Allah ﷺ, raised in his household from childhood, and the first child to believe. Later he married the Prophet's ﷺ daughter Fatimah.
❝ HadithDuring the siege of Khaybar the Messenger of Allah ﷺ said: tomorrow I will give the banner to a man at whose hands Allah will grant victory; he loves Allah and His Messenger, and Allah and His Messenger love him. The Companions spent the night wondering who would be given it. In the morning he called for 'Ali, whose eyes were sore, applied his saliva to them and prayed, and he was healed as if he had never had pain. The banner was given to him.Sahih al-Bukhari 3701 · Sahih
❝ HadithSetting out for Tabuk, the Messenger of Allah ﷺ left 'Ali in Madinah. Hurt, 'Ali said: are you leaving me among the women and children? He ﷺ said: are you not pleased to be to me as Harun was to Musa — except that there is no prophet after me?Sahih al-Bukhari 3706 · Sahih