Musnad Ahmad 28:173

Yahya ibn Ishaq narrated to us, Ibn Lahi'ah narrated to us, from al-Harith ibn Yazid, from Ibn Hujayrah, from Abdullah ibn Amr, from the Prophet, peace and blessings of Allah be upon him, who said: "Indeed, the guided Muslim—who strives for correctness—is like the one who is fasting and praying, who does not cease from the fasting and the prayer, because of his good intention and his following of the Messenger of Allah, peace and blessings of Allah be upon him."