صحیح ابن حبان
Ibn Hibban
كتاب الصلاة
Book of Prayer
باب الأذان - ذكر البيان بأن الله جل وعلا إنما يغفر للمؤذن ويدخله الجنة بأذانه إذا كان ذلك على يقين منه
Chapter on Adhan - Clarification that Allah forgives and admits the muezzin to Paradise if he calls with certainty.
1 hadith
Hadith 1667
Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates: We were with the Prophet (peace and blessings be upon him) near a cluster of date palms. Sayyiduna Bilal (may Allah be pleased with him) stood up and began to give the adhan. When he finished, the Prophet (peace and blessings be upon him) said: "Whoever says the same words with certainty that he has said, that person will enter Paradise."