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."
Sahih Muslim Book 4, Hadith 4
← Previous Hadith 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 was ordered to repeat the phrases twice in Adhan, and once in Iqama.

Sahih Muslim Book 4, Hadith 3 Next Hadith → Bilal was commanded (by the Holy Prophet) to repeat the phrases twice in Adhan, and once in lqama.

Sahih Muslim Book 4, Hadith 5