Musnad Ahmad 30:2571

Ibn Idris narrated to us, he said: I heard Suhayl ibn Abi Salih mentioning from his father, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "If you pray after Jumu'ah, then pray four. If you are in a hurry for something, then pray two, and two when you return." Ibn Idris said: "And I do not know if this is in the hadith of the Messenger of Allah (peace and blessings of Allah be upon him) or not."