Musnad Ahmad 109:3

Yahya ibn Ishaq narrated to us, he said: Ibn Lahi'ah informed me, from al-Harith ibn Yazid, from Kathir al-A'raj, from Abu Fatimah, he said: The Messenger of Allah, peace and blessings of Allah be upon him, said: "O Abu Fatimah, increase in prostration, for there is no man who prostrates a prostration to Allah, except that Allah raises him a degree by it."