Musnad Ahmad 30:3414

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: "The best day upon which the sun has risen is Friday. On it, Adam was created, on it he was entered into Paradise, and on it he was cast down from it. And on it the Hour will be established. And in it is an hour; no believer happens to be praying during it—and he clenched his fingers, indicating it is a short time—asking Allah, the Almighty and Majestic, for good, but He will grant it to him."