Maliks Muwatta Book 14, Hadith Number 7.
Section : The Prohibition against Spitting towards the Qibla.
Yahya related to me from Malik from Yahya ibn Said that Said ibn al-Musayyab said, “The Messenger of Allah, may Allah bless him and grant him peace, prayed towards the Baytal-Maqdis for sixteen months after arriving in Madina. Then the qibla was moved, two months before the battle of Badr.”