Musnad Ahmad 21:16

Qutaybah ibn Sa'id narrated to us, Layth ibn Sa'd narrated to us, from Ibn al-Had, from Muhammad ibn Ibrahim ibn al-Harith, from 'Amir ibn Sa'd, from al-'Abbas ibn 'Abd al-Muttalib, that he heard the Messenger of Allah, peace and blessings of Allah be upon him, saying: "He has tasted the flavor of faith who is pleased with Allah as a Lord, with Islam as a religion, and with Muhammad as a Prophet."