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. (JA)
English reference (JA): Vol. 1, Book 7, Hadith 675 (JA)
Arabic reference (JA): Book 7, Hadith 682 (JA)