While the people were offering the Fajr prayer at Quba' (near Medina), someone came to them andsaid: "It has been revealed to Allah's Messenger (ﷺ) tonight, and he has been ordered to pray facing theKa`ba." So turn your faces to the Ka`ba. Those people were facing Sham (Jerusalem) so they turnedtheir faces towards Ka`ba (at Mecca).