الصلاة : Hadeeth No:737
Anas b. Malik 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 was ordered to repeat the phrases twice in Adhan, and once in Iqama....
الأشربة : Hadeeth No:4905
This hadith has been narrated on the authority of Yahya b. Abu Kathir with the same chain of transmitters....