Musnad Ahmad 30:3403

Yazid narrated to us, Muhammad informed us, from Abu Salamah, from Abu Hurairah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "No one among you will be saved by his deeds." We said: "Not even you, O Messenger of Allah?" He said: "Not even me, unless Allah covers me with mercy from Him. But strive for correctness and be steadfast."