(2) باب الأَمْرِ بِشَفْعِ الأَذَانِ وَإِيتَارِ الإِقَامَةِ
Anas reported:
Bilal was commanded (by the Holy Prophet) to repeat the phrases twice in Adhan, and once in lqama. (RU)
Reference (RU): Sahih Muslim 378 d (RU)
In-book reference (RU): Book 4, Hadith 5 (RU)
USC-MSA web (English) reference(deprecated numbering scheme): Book 4, Hadith 739 (RU)