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." (ES)
English reference (ES): Vol. 5, Book 44, Hadith 3090 (ES)
Arabic reference (ES): Book 47, Hadith 3370 (ES)