The Rites of Hajj (Kitab Al-Manasik Wa'l-Hajj)
11/76. Chapter:
The Salat At Mina
Sunan Abi Dawud
حَدَّثَنَا هَنَّادُ بْنُ السَّرِيِّ، عَنْ أَبِي الأَحْوَصِ، عَنِ الْمُغِيرَةِ، عَنْ إِبْرَاهِيمَ، قَالَ إِنَّ عُثْمَانَ صَلَّى أَرْبَعًا لأَنَّهُ اتَّخَذَهَا وَطَنًا .
Narrated Ibrahim: Uthman prayed four rak'ahs (at Mina) for he made it his home (for settlement).
Reference : Sunan Abi Dawud 1962In-book reference : Book 11, Hadith 242English translation : Book 10, Hadith 1957