Musnad Ahmad 28:170

Surayj narrated to us, Baqiyyah narrated to us, from Mu'awiyah ibn Sa'id, from Abu Qubayl, from Abdullah ibn Amr ibn al-'As, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever dies on the day of Friday or the night of Friday, he is protected from the trial of the grave."