An-Nasr bin Sufyan narrated that he heard Abu Hurairah say:
"We were with the Messenger of Allah (ﷺ) and Bilal stood up and gave the call. When he fell silent the Messenger of Allah (ﷺ) said: 'Whoever says the same as this (what the Mu'adhdhin) with certainty, he will enter Paradise. (AR)
English reference (AR): Vol. 1, Book 7, Hadith 675 (AR)
Arabic reference (AR): Book 7, Hadith 682 (AR)