(3) باب السُّنَّةِ فِي الأَذَانِ
It was narrated that Bilal said:
"The Messenger of Allah commanded me (with Tathwib) in the Adhan for Fajr, and he forbade me to do so in the Adhan for 'Isha'." (ES)
Reference (ES): Sunan Ibn Majah 715 (ES)
In-book reference (ES): Book 3, Hadith 10 (ES)
English translation (ES): Vol. 1, Book 3, Hadith 715 (ES)