It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that the people were performing the morning prayer in the mosque of Quba, when a man came and said that last night the Qur'an was revealed to the Prophet (peace and blessings be upon him) in which he was commanded to turn his face towards the Ka'bah during prayer. Upon hearing this, those people turned their faces towards the Ka'bah during the prayer itself.