Sunan Abi Dawud 508
سنن أبي داود#508SahihAnas reported; Bilal was commanded to pronounce Adhan in double pairs and IQAMAH in single pairs. Hammam added in his version; “except IQAMAH”
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih Bukhari (605) Sahih Muslim (378)
In-book reference: 2:118