Musnad Abu Ya'la al-Mawsili 140:35

Ishaq ibn Abi Isra'il narrated to us, Hatim ibn Isma'il narrated to us, from Humayd ibn Sakhr, from Yazid al-Raqashi, from Anas ibn Malik, who said: The Messenger of Allah (peace be upon him) said: "Whoever prays the morning prayer, then his protection (dhimmah) is violated, then the sanctuary of Allah has been made lawful, and his protection has been breached, and I am the seeker of his protection."