Musnad Ahmad 30:2570

Talid ibn Sulayman narrated to us, he said: Abu al-Hajaf narrated to us, from Abu Hazim, from Abu Hurayrah, he said: The Prophet, peace and blessings of Allah be upon him, looked at Ali, al-Hasan, al-Husayn, and Fatimah, and said: "I am at war with those who war against you, and at peace with those who make peace with you."