The Book on Salat (Prayer)
2/138. Chapter:
What Has Been Related About The Beginning Of The Qiblah
Jami at-Tirmidhi
حَدَّثَنَا هَنَّادٌ، حَدَّثَنَا وَكِيعٌ، عَنْ سُفْيَانَ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ، عَنِ ابْنِ عُمَرَ، قَالَ كَانُوا رُكُوعًا فِي صَلاَةِ الصُّبْحِ . قَالَ أَبُو عِيسَى وَحَدِيثُ ابْنِ عُمَرَ حَدِيثٌ صَحِيحٌ .
Ibn Umar said: "They Were Bowing During The Subh (Fajr) Prayer."
Reference : Jami` at-Tirmidhi 341In-book reference : Book 2, Hadith 193English translation : Vol. 1, Book 2, Hadith 341