Musannaf Ibn Abi Shayba 37:282

Abu Mu'awiyah narrated to us, from al-A'mash, from Zayd ibn Wahb, who said: A man from the hypocrites died, and Hudhayfah did not pray over him. Umar said to him, "Is he from the people [the hypocrites]?" He said, "Yes." Umar said to him, "By Allah, am I among them?" He said, "No, and I will not inform anyone about it after you."