As for those who claim that it is a sunnah whose omission entails neither sin nor punishment, this view is mistaken. The adhān is the hallmark of the abode of Islam. It is established in the Sahīh that “the Prophet, peace and blessings be upon him, made the lawfulness of attacking a settlement’s inhabitants dependent on their abandoning it. He would perform the dawn prayer and then wait to see: if he heard a caller to prayer, he would not raid them; otherwise, he would.”
In the Sunan of Abū Dāwūd and al-Nasā’ī, Abū al-Dardā’ reported: I heard the Messenger of Allah, peace and blessings be upon him, say:
“Whenever there are three people in a village among whom the adhān is not called and prayer is not established, Satan gains mastery over them. So keep to the congregation, for the wolf devours the stray sheep.”
Allah Most High says:
“Satan has gained mastery over them and caused them to forget the remembrance of Allah. Those are the party of Satan. Indeed, it is the party of Satan who are the losers.”
As for repeating the two testimonies of faith aloud after reciting them quietly, or omitting this repetition; saying ‘Allah is greatest’ twice or four times; and repeating the phrases of the iqāmah twice or saying them once, Sahīh Muslim and the Sunan contain the report of Abū Mahdhūrah: “The Prophet, peace and blessings be upon him, taught him the adhān in the year of the conquest of Mecca. The office of calling the adhān in Mecca remained with him and his descendants. It is established that he taught him the adhān and iqāmah, including the repetition of the two testimonies of faith aloud after reciting them quietly.”
His report has “saying ‘Allah is greatest’ twice,” as in Sahīh Muslim, and also “four times,” as in the Sunan of Abū Dāwūd and elsewhere. His report also states that he taught him to repeat the phrases of the iqāmah twice.
It is established in the Sahīh that Anas ibn Mālik said:
“When the people grew numerous”—he said—“they discussed having something recognizable by which to know the time of prayer