جامع الترمذي

Narrated Usamah bin Zaid: "I was sitting [with the Prophet (ﷺ)] when 'Ali and Al-'Abbas came seeking permission to enter. They said: 'O Usamah, seek permission for us from the Messenger of Allah (ﷺ).' So I said: 'O Messenger of Allah, 'Ali and Al-'Abbas seek permission to enter.' He said: 'Do you know what has brought them?' I said: 'No [I do not know].' So the Prophet (ﷺ) said: 'But I know, grant them permission.' So they entered and said: 'O Messenger of Allah, we have come to you, to ask you which of your family is most beloved to you.' He said: 'Fatimah bint Muhammad.' So they said: 'We did not come to ask you about (immediate) family.' He said: 'The most beloved of my family to me is the one whom Allah favored and I favored, Usamah bin Zaid.' They said: 'Then who?' He said: 'Then 'Ali bin Abi Talib.' Al-'Abbas said: 'O Messenger of Allah, you have made your uncle the last of them.' He said: 'Indeed, 'Ali has preceded you in emigration.'"