Sahih Muslim Book - 5, Hadith - 1180

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِى شَيْبَةَ حَدَّثَنَا عَفَّانُ حَدَّثَنَا حَمَّادُ بْنُ سَلَمَةَ عَنْ ثَابِتٍ عَنْ أَنَسٍ أَنَّ رَسُولَ اللَّهِ -صلى الله عليه وسلم- كَانَ يُصَلِّى نَحْوَ بَيْتِ الْمَقْدِسِ فَنَزَلَتْ (قَدْ نَرَى تَقَلُّبَ وَجْهِكَ فِى السَّمَاءِ فَلَنُوَلِّيَنَّكَ قِبْلَةً تَرْضَاهَا فَوَلِّ وَجْهَكَ شَطْرَ الْمَسْجِدِ الْحَرَامِ) فَمَرَّ رَجُلٌ مِنْ بَنِى سَلِمَةَ وَهُمْ رُكُوعٌ فِى صَلاَةِ الْفَجْرِ وَقَدْ صَلَّوْا رَكْعَةً فَنَادَى أَلاَ إِنَّ الْقِبْلَةَ قَدْ حُوِّلَتْ. فَمَالُوا كَمَا هُمْ نَحْوَ الْقِبْلَةِ.

It was narrated from Anas that the Messenger of Allah (s.a.w) used to pray facing towards Bait Al-Maqdis, then it was revealed: "Verily, We have seen the turning of your face towards the heaven. Surely, We shall turn you to a Qiblah (prayer direction) that shall please you, so turn your face in the direction of Al-Masjid Al-Haram..." A man passed by Banu Salamah while they were bowing during Fajr prayer, and they had prayed one Rak'ah. He called out: "The Qiblah has been changed," and they turned as they were, towards the Qiblah.