As'Salamu Alaikum wa Rahamatullahi wa Barakatuhu,

The word adhaan in Arabic means announcing or proclaiming.

In sharee�ah terminology it means announcing the time of prayer.

Lets see how the Adha'an got started :

Narrated by Abu Dawood, 499; classed as saheeh by Ibn Khuzaymah, 1/191 and Ibn Hibbaan, 4/572. al-Tirmidhi narrated that Imam al-Bukhaari deemed it saheeh, as it says in Sunan al-Bayhaqi, 1/390

It was narrated that �Abd-Allaah ibn Zayd said:

 When the Messenger of Allaah (sallal lahu alahi wasallam ) ordered that a bell should be made so that it could be struck to call the people to prayer,

A man walked around me whilst I was sleeping [i.e., in a dream], carrying a bell in his hand. I said, �O slave of Allaah, will you sell this bell?�

He asked, �What will you do with it?�

 I said, �We will call the people to prayer.�

 He said, �Shall I not tell you of something better than that?�

I said, �Yes.�

 He said, �Say: Allaahu akbar, Allaah akbar, Allaahu akbar, Allaah akbar; ash-hadu an laa ilaah ill-Allaah, ash-hadu an laa ilaah ill-Allaah; ash-hadu anna Muhammadan rasool-Allaah, ash-hadu anna Muhammadan rasool-Allaah; hayya �ala al-salaah, hayya �ala al-salaah; hayya �ala�l-falaah, hayya �ala�l-falaah; Allaahu akbar, Allaahu akbar; Laa ilaaha ill-Allaah

(Allaah is most Great, Allaah is most Great, Allaah is most Great, Allaah is most Great. I bear witness that there is no god except Allaah, I bear witness that there is no god except Allaah. I bear witness that Muhammad is the Messenger of Allaah, I bear witness that Muhammad is the Messenger of Allaah. Come to prayer, come to prayer; come to success, come to success. Allaah is most Great, Allaah is most Great, there is no god except Allaah).�

Then he went a short distance away from me and said: �And when the prayer is about to begin (iqaamah), say:

Allaahu akbar, Allaah akbar; ash-hadu an laa ilaah ill-Allaah; ash-hadu anna Muhammadan rasool-Allaah; hayya �ala al-salaah, hayya �ala�l-falaah; qad qaamat il-salaah, qad qaamat il-salaah (prayer is about to begin); Allaahu akbar, Allaahu akbar; Laa ilaaha ill-Allaah

The following morning, I went to the Messenger of Allaah (sallal lahu alaihi wasallam ) and told him what I had seen.

He said, �This is a true dream, insha Allah. Get up with Bilaal and teach him what you saw, for he has a more melodious voice than you.� So I got up with Bilaal and taught him, and he gave the call to prayer.

 �Umar ibn al-Khattaab heard that in his house and he came out, dragging his lower garment and saying, �By the One Who sent you with the truth, O Messenger of Allaah, I saw the same as he saw!� The Messenger of Allaah (peace and blessings of Allaah be upon him) said, �To Allaah be praise.�

Narrated by Abu Dawood, 500; al-Nasaa�i, 647; classed as saheeh by al-Albaani in Saheeh Abi Dawood.

 It was narrated that Ibn �Umar (may Allaah be pleased with him) said: In the first adhaan after the word al-falaah it said: Al-salaatu khayrun min al-nawm, al-salaatu khayrun min al-nawm (prayer is better than sleep, prayer is better than sleep).

Virtues of Adha'an

Narrated by al-Bukhaari, 590; Muslim, 437.

Abu Hurayrah (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: �If the people knew what there is in the call to prayer and the first row, and they had no other way but drawing lots, then they would draw lots.�

It was narrated that Mu�aawiyah (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: The muezzins will have the longest necks of the people on the Day of Resurrection.� Narrated by Muslim, 387

(Narrated by al-Tirmidhi, 212; Abu Dawood, 437; Ahmad, 12174 � this version narrated by him. Classed as saheeh by al-Albaani in Saheeh Abi Dawood, 489).
 It was narrated that Anas said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: �Du�aa� is not rejected between the adhaan and iqaamah, so make du�aa�.�

How to reply Adha'an

Narrated by Muslim, 385
It was narrated that �Umar ibn al-Khattaab said: the Messenger of Allaah (peace and blessings of Allaah be upon him) said: �If the muezzin says �Allaahu akbar, Allaahu akbar� and one of you says, �Allaahu akbar, Allaahu akbar�; then he says �Ashhadu an laa ilaaha ill-Allaah� and you say �Ashhadu an laa ilaaha ill-Allaah�; then he says, �Ash-hadu anna Muhammadan Rasool Allaah� and you say, �Ash-hadu anna Muhammadan Rasool Allaah�; then he says, �Hayya �ala�l-salaah� and you say �Laa hawla wa laa quwwata illa Billaah�; then he says, �Hayya �ala�l-falaah� and you say �Laa hawla wa laa quwwata illa Billaah�; then he says, �Allaahu akbar, Allaahu akbar� and you say, �Allaahu akbar, Allaahu akbar�; then he says �Laa ilaaha ill-Allaah� and you say, �Laa ilaaha ill-Allaah� from the heart, you will enter Paradise.�