Quran: 002-114

 We have seen thee [O Prophet] often turn thy face towards heaven [for guidance]: and now We shall indeed make thee turn in prayer in a direction which will fulfil thy desire. Turn, then, thy face towards the Inviolable House of Worship; and wherever you all may be, turn your faces towards it [in prayer]. And, verily, those who have been vouchsafed revelation aforetime know well that this [commandment] comes in truth from their Sustainer; and God is not unaware of what they do.  Quran 2-114