Ali ibn Ishaq narrated to us, Abdullah ibn Mubarak informed us, Sufyan informed us, from Mansur, from Sa'd ibn Ubaydah, and he mentioned with his chain and its meaning, and said: "Perform ablution as you do for prayer." And he said: "Make these the last words you speak." He said: So I repeated it to the Prophet, peace and blessings be upon him, and when I reached: "I believe in Your Book which You have revealed," I said: "And in Your Messenger." He said: "No, but say: 'And in Your Prophet whom You have sent.'"