Musnad Ahmad 1583

It was narrated that Sa"d bin Abi Waqqas said: The Messenger of Allah (ﷺ) left "Ali bin Abi Talib in charge [of Madinah] during the campaign to Tabook, ‘Ali said: O Messenger of Allah, are you leaving me behind with the women and children? He said: “Does it not please you to be to me as Haroon was to Moosa? Except that there will be no Prophet (ﷺ) after me.“