أَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، وَمُحَمَّدُ بْنُ الْمُثَنَّى، عَنْ يَحْيَى، عَنْ عَبْدِ الْمَلِكِ، قَالَ حَدَّثَنَا سَعِيدُ بْنُ جُبَيْرٍ، عَنِ ابْنِ عُمَرَ، قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يُصَلِّي عَلَى دَابَّتِهِ وَهُوَ مُقْبِلٌ مِنْ مَكَّةَ إِلَى الْمَدِينَةِ وَفِيهِ أُنْزِلَتْ ‏{‏ فَأَيْنَمَا تُوَلُّوا فَثَمَّ وَجْهُ اللَّهِ ‏}‏ ‏.‏

It was narrated that Ibn 'Umar said: "The Messenger of Allah (PBUH) used to pray while on his animal when he was coming back from Makkah to Madinah. Concerning this, the verse was revealed: So wherever you turn (yourselves or your faces) there is the Face of Allah.'" [1] [1] Al-Baqarah 2:115. Translation Not Available

Book Ref: Sunan An Nisai Book 5 Hadith 491
Web Ref:  Sunan An Nisai Vol 1 Book 5 Hadith 492