Narrated Anas:

The people mentioned the fire and the bell (they suggested those as signals to indicate the starting of prayers), and by that they mentioned the Jews and the Christians. Then Bilal was ordered to pronounce Adhan for the prayer by saying its wordings twice, and for the Iqama (the call for the actual standing for the prayers in rows) by saying its wordings once. (Iqama is pronounced when the people are ready for the prayer).

Narrated Ibn `Umar:

When the Muslims arrived at Medina, they used to assemble for the prayer, and used to guess the time for it. During those days, the practice of Adhan for the prayers had not been introduced yet. Once they discussed this problem regarding the call for prayer. Some people suggested the use of a bell like the Christians, others proposed a trumpet like the horn used by the Jews, but `Umar was the first to suggest that a man should call (the people) for the prayer; so Allah's Apostle ordered Bilal to get up and pronounce the Adhan for prayers.

Narrated Anas:

Bilal was ordered to repeat the wording of the Adhan for prayers twice, and to pronounce the wording of the Iqama once except "Qad-qamat-is-salat".

Narrated Anas bin Malik:

When the number of Muslims increased they discussed the question as to how to know the time for the prayer by some familiar means. Some suggested that a fire be lit (at the time of the prayer) and others put forward the proposal to ring the bell. Bilal was ordered to pronounce the wording of Adhan twice and of the Iqama once only.

Narrated Abu Qilaba:

Anas said, "Bilal was ordered to pronounce the wording of Adhan twice and of Iqama once only." The sub narrator Isma`il said, "I mentioned that to Aiyub and he added (to that), "Except Iqama (i.e. Qad-qamat-is-salat which should be said twice).

Narrated Abu Huraira:

Allah's Apostle said, "When the Adhan is pronounced Satan takes to his heels and passes wind with noise during his flight in order not to hear the Adhan. When the Adhan is completed he comes back and again takes to his heels when the Iqama is pronounced and after its completion he returns again till he whispers into the heart of the person (to divert his attention from his prayer) and makes him remember things which he does not recall to his mind before the prayer and that causes him to forget how much he has prayed."

Narrated `Abdur-Rahman:

Abu Sa`id Al-Khudri told my father, "I see you liking sheep and the wilderness. So whenever you are with your sheep or in the wilderness and you want to pronounce Adhan for the prayer raise your voice in doing so, for whoever hears the Adhan, whether a human being, a jinn or any other creature, will be a witness for you on the Day of Resurrection." Abu Sa`id added, "I heard it (this narration) from Allah's Apostle."

Narrated Humaid:

Anas bin Malik said, "Whenever the Prophet went out with us to fight (in Allah's cause) against any nation, he never allowed us to attack till morning and he would wait and see: if he heard Adhan he would postpone the attack and if he did not hear Adhan he would attack them." Anas added, "We reached Khaibar at night and in the morning when he did not hear the Adhan for the prayer, he (the Prophet ) rode and I rode behind Abi Talha and my foot was touching that of the Prophet. The inhabitants of Khaibar came out with their baskets and spades and when they saw the Prophet they shouted 'Muhammad! By Allah, Muhammad and his army.' When Allah's Apostle saw them, he said, "Allahu-Akbar! Allahu-Akbar! Khaibar is ruined. Whenever we approach a (hostile) nation (to fight), then evil will be the morning of those who have been warned."

Narrated Abu Sa`id Al-Khudri:

Allah's Apostle said, "Whenever you hear the Adhan, say what the Mu'adh-dhin is saying.

Narrated `Isa bin Talha:

that he had heard Muawiya repeating the words of Adhan up to "Wa ash-hadu anna Muhammadan rasulul-lah (and I testify that Muhammad is Allah's Apostle.)"

Narrated Yahya as above (586) and added:

"Some of my companions told me that Hisham had said, "When the Mu'adh-dhin said, "Haiyi `alas-sala (come for the prayer)." Muawiya said, "La hawla wala quwata illa billah (There is neither might nor any power except with Allah)" and added, "We heard your Prophet saying the same."

Narrated Jabir bin `Abdullah:

Allah's Apostle said, "Whoever after listening to the Adhan says, 'Allahumma Rabba hadhihi-d-da`watit-tammah, was-salatil qa'imah, ati Muhammadan al-wasilata wal-fadilah, wa b`ath-hu maqaman mahmudan-il-ladhi wa`adtahu' [O Allah! Lord of this perfect call (perfect by not ascribing partners to You) and of the regular prayer which is going to be established, give Muhammad the right of intercession and illustriousness, and resurrect him to the best and the highest place in Paradise that You promised him (of)], then my intercession for him will be allowed on the Day of Resurrection".

Narrated Abu Huraira:

Allah's Apostle said, "If the people knew the reward for pronouncing the Adhan and for standing in the first row (in congregational prayers) and found no other way to get that except by drawing lots they would draw lots, and if they knew the reward of the Zuhr prayer (in the early moments of its stated time) they would race for it (go early) and if they knew the reward of `Isha' and Fajr (morning) prayers in congregation, they would come to offer them even if they had to crawl."

Narrated `Abdullah bin Al-Harith:

Once on a rainy muddy day, Ibn `Abbas delivered a sermon in our presence and when the Mu'adh-dhin pronounced the Adhan and said, "Haiyi `ala-s-sala(t) (come for the prayer)" Ibn `Abbas ordered him to say 'Pray at your homes.' The people began to look at each other (surprisingly). Ibn `Abbas said. "It was done by one who was much better than I (i.e. the Prophet or his Mu'adh-dhin), and it is a license.'

Narrated Salim bin `Abdullah:

My father said that Allah s Apostle said, "Bilal pronounces 'Adhan at night, so keep on eating and drinking (Suhur) till Ibn Um Maktum pronounces Adhan." Salim added, "He was a blind man who would not pronounce the Adhan unless he was told that the day had dawned."