Musnad Ahmad 830:42

Muhammad ibn Yazid narrated to us, Al-Awwam ibn Hawshab informed us, from Sa'id ibn Jumhan, from Ibn Abi Bakrah, from his father, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "You will certainly descend upon a land called Al-Basrah, or Al-Basirah, upon a river called the Tigris." He mentioned its meaning. Al-Awwam said: "The children of Qantura are the Turks."