Sayyiduna Anas (may Allah be pleased with him) narrates: Sayyiduna Bilal (may Allah be pleased with him) used to say the words of the adhan twice and the words of the iqamah once, except for the words "Qad qamatis salah," which he used to say twice.

Sayyiduna Anas (may Allah be pleased with him) narrates: The Noble Prophet (peace and blessings be upon him) instructed Sayyiduna Bilal (may Allah be pleased with him): to pronounce the words of the adhan twice and the words of the iqamah once.

Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates: The Noble Prophet (peace and blessings be upon him) said:“Whoever gives the call to prayer (adhan) for twelve years, Paradise will become obligatory for him, and for every adhan sixty good deeds will be written, and for every iqamah thirty good deeds will be written.”

Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates: The Noble Prophet (peace and blessings be upon him) said: "Whoever gives the call to prayer (adhan) for twelve years, Paradise will become obligatory for him, and due to his giving the adhan, for every adhan sixty good deeds will be written for him, and for every iqamah thirty good deeds will be written for him."

Sayyiduna Salamah bin Akwa’ (may Allah be pleased with him) narrates: In the blessed time of the Prophet (peace and blessings be upon him), the words of the adhan were pronounced twice and the words of the iqamah were pronounced once.

It is narrated about Sayyiduna Salamah bin Akwa’ (may Allah be pleased with him): When he was unable to perform the prayer in congregation, he would give the adhan (call to prayer) and say the iqamah (second call to prayer) (he would say the words of the iqamah twice).

Imam Muhammad bin Ali narrates from his father the statement of Sayyiduna Ali (may Allah be pleased with him): Jibreel (peace be upon him) descended with the words of Iqamah separately; the Noble Prophet (peace and blessings be upon him) prescribed reciting the words twice in the Adhan as Sunnah.

Sayyiduna Abu Rafi’ (may Allah be pleased with him) narrates: I saw the Prophet (peace and blessings of Allah be upon him) and I heard Sayyiduna Bilal (may Allah be pleased with him) giving the adhan in front of the Prophet (peace and blessings of Allah be upon him). He would say the words (of the adhan) twice each, while he would say the words of the iqamah once each.

Muhammad bin Abdullah narrates: My father (Sayyiduna Abdullah bin Zaid, may Allah be pleased with him) narrated this noble hadith to me: When the Prophet Muhammad (peace and blessings be upon him) ordered for a bell (naqus) to be used for prayer, I saw in a dream a person who came to me and taught me this matter. He mentioned the words of the adhan twice and the words of the iqamah once. At the time of the morning prayer, I presented myself before the Prophet Muhammad (peace and blessings be upon him) and related this dream. He (peace and blessings be upon him) said: "If Allah wills, this dream will prove true. Stand with Bilal and teach him what you have seen, for his voice is louder than yours." When Sayyiduna Umar (may Allah be pleased with him) heard this, he said: "By the One Who has sent you with the truth, I too saw a dream just like he saw." So the Prophet Muhammad (peace and blessings be upon him) said: "Then all praise is due to Allah (Who has granted us this guidance)."

Sayyiduna Abdullah bin Zaid (may Allah be pleased with him) narrates: In the blessed era of the Prophet Muhammad (peace be upon him), the words of the adhan and iqamah were even (paired). The narrators of this narration are Ibn Abi Layla and Qadi Muhammad bin Abdur Rahman, who were considered weak in the science of hadith because their memory was weak. Similarly, it is not established that Ibn Abi Layla heard hadith from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both).