Musnad Ahmad 33:494

Hassan narrated to us, Ibn Lahi'ah narrated to us, Abu al-Zubayr narrated to us, he said: I asked Jabir, may Allah be pleased with him, about prostration. He said: I heard the Messenger of Allah, peace and blessings of Allah be upon him, commanding that one should be moderate in prostration, and that a man should not prostrate while he is spreading out his forearms.