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 `alassala (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-dda 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".

And it is said that when there was a disagreement among some people regarding giving the adhan, Sa’d bin Abi Waqqas had them draw lots (to decide).

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."

And the companion Sulaiman bin Surad spoke during the adhan, and Hasan al-Basri said that if a person laughs while giving the adhan or the takbir, there is no harm.

Narrated `Abdullah bin Al-Harith: Once on a rainy muddy day, Ibn `Abbas delivered a sermon in our presence and when the Mu'adhdhin 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."

Narrated Hafsa: When the Mu'adh-dhin pronounced the Adhan for Fajr prayer and the dawn became evident the Prophet ordered a two rak`at light prayer (Sunna) before the Iqama of the compulsory (congregational) prayer.