It is narrated from Abdullah bin Muhairiz (may Allah have mercy on him) that he was an orphan and was brought up in the lap of Sayyiduna Abu Mahdhurah (may Allah be pleased with him) until Sayyiduna Abu Mahdhurah (may Allah be pleased with him) prepared him and sent him to Syria. He says: I said to Sayyiduna Abu Mahdhurah (may Allah be pleased with him): Uncle, I am going to Syria, and I expect that (there) I will be asked about your call to prayer (adhan), so please tell me something. Sayyiduna Abu Mahdhurah (may Allah be pleased with him) said: I went out with some people; we were on the road to Hunayn when the Messenger of Allah (peace and blessings of Allah be upon him) was returning from Hunayn. On the way, we met, and the muezzin of the Messenger of Allah (peace and blessings of Allah be upon him) called the adhan for prayer in front of him. We heard the voice of the muezzin; we were at some distance. We began to imitate the loud voice of the muezzin, mocking him. The Messenger of Allah (peace and blessings of Allah be upon him) heard the voices and sent for us until we stood before him. The Messenger of Allah (peace and blessings of Allah be upon him) said: "Which one of you is the one whose loud voice I heard?" The people pointed towards me and spoke the truth. So the Messenger of Allah (peace and blessings of Allah be upon him) let all of them go and kept me back and said: "Stand up and call the adhan for prayer." I stood up, and at that moment, the most disliked to me was the Messenger of Allah (peace and blessings of Allah be upon him) and his command. (At that time, they were not Muslims.) I stood before the Messenger of Allah (peace and blessings of Allah be upon him), and the Messenger of Allah (peace and blessings of Allah be upon him) himself taught me the adhan. He said: «اللَّهُاَكْبَرُاللَّهُاَكْبَرُ،اللهُأَكْبَرُاللَّهُاَكْبَرُ،اَشْهَدُأَنْلَاإِلَهَإِلَّااللَّهُ،أَشْهَدُأَنْلَاإِلَهَإِلَّااللهُ،اَشْهَدُأَنَّمُحَمَّدًارَسُولُاللهِ،اَشْهَدُأَنَّمُحَمَّدًارَسُولُاللهِ», then he said: Say again: «اَشْهَدُاَنْلَّاإِلَهَإِلَّااللهُ،اَشْهَدُاَنْ لا إِلَهَإِلَّااللَّهُ،اَشْهَدُأَنَّمُحَمَّدًارَسُوْلُاللهِ،اَشْهَدُأَنَّمُحَمَّدًارَسُولُاللهِ،حَيَّىعَلَىالصَّلاةِ،حَيَّعَلَىالصَّلَاةِ،حَيَّعَلَىالْفَلَاحِ،حَيَّعَلَىالْفَلَاحِ،اللهُأَكْبَرُاللهُأَكْبَرُلَاإِلَهَإِلَّااللهُ». Then he called me when the adhan was completed, then he gave me a pouch in which there was silver. Then the Messenger of Allah (peace and blessings of Allah be upon him) placed his hand on my forehead, then on my face, then spread it over my chest, then the Messenger of Allah (peace and blessings of Allah be upon him) placed his hand on my navel, then the Messenger of Allah (peace and blessings of Allah be upon him) made supplication «بَارِكَاللَّهُفِيكَوَبَارِكَعَلَيْكَ» (then faith had penetrated inside). I said: O Messenger of Allah! Make me the muezzin of Makkah. The Messenger of Allah (peace and blessings of Allah be upon him) said: "You have been appointed." So all the dislike that was in my heart for the Messenger of Allah (peace and blessings of Allah be upon him) disappeared, and love took its place. So I went to the governor of Makkah, ‘Attab bin Asid (may Allah be pleased with him), and continued to call the adhan before him by the order of the Messenger of Allah (peace and blessings of Allah be upon him). Ibn Jurayj (may Allah have mercy on him) says: Imam Malik (may Allah have mercy on him) informed us that I heard from the family of Abu Mahdhurah (may Allah be pleased with him) in the same way as Abdullah bin Muhairiz (may Allah have mercy on him) reported.
Hadith Referenceالسنن المأثورة / باب ما جاء في الأذان / 274
Hadith Takhrijسنن ابی داؤد، الصلاة، باب كيف الأذان، رقم: 503 وقال الالباني: صحيح، سنن نسائی، الاذان، باب كيف الاذان، رقم: 632، سنن ابن ماجه، الاذان، باب الترجيع في الأذان، رقم: 708