باب الأَمْرِ بِشَفْعِ الأَذَانِ وَإِيتَارِ الإِقَامَةِ:
Chapter: The Command to say the phrases of the Adhan twice and the phrases of the iqamah once, except the phrase, "Prayer is about to begin," which is to be said twice
Anas reported: Bilal (RA) was commanded (by the Apostle of Allah (ﷺ) ) to repeat (the phrases of) Adhan twice and once in Iqama. The narrator said: I made a men- tion of it before Ayyub who said: Except for saying: Qamat-is-Salat [the time for prayer has come].
Anas bin Malik (RA) reported: They (the Companions) discussed that they should know the timings of prayer by means of something recognized by all. Some of them said that fire should be lighted or a bell should be rung. But Bilal (RA) was ordered to repeat the phrases twice in Adhan, and once in Iqama.
This hadith is transmitted by Khalid Hadhdha with the same chain of transmitters (and the words are): When the majority of the people discussed they should know, like the hadith narrated by al-Thaqafi (mentioned above) except for the words:" They (the people) should kindle fire."