Narrated Anas bin Malik:"The Prophet (ﷺ) sent Abu Bakr with the (announcement of) Bara'ah (the declaration to publicize the disavowal of the idolaters). Then he summoned him and said: 'It is not right for anyone to convey this except a man among my family.'"So he called for 'Ali and gave it to him

English translation · Jami' at-Tirmidhi