Musannaf Ibn Abi Shayba 33:619

Waki’ narrated to us, from Sufyan, from his father, from Mundhir, from al-Rabi’ ibn Khuthaym, that he made a will at the time of his death, and he said: "This is what al-Rabi’ ibn Khuthaym affirmed upon himself, and he called Allah as a witness over it, and sufficient is Allah as a witness, a rewarder for His righteous servants, and a recompenser: That I am pleased with Allah as a Lord, with Islam as a religion, and with Muhammad as a Prophet. And I am pleased for myself and for whoever obeys me, that I worship Him among the worshippers, that I praise Him among the praisers, and that I offer sincere counsel to the community of the Muslims."