Musnad Ahmad 1153:315

Ya'la narrated to us, Qudamah—meaning Ibn Abdullah al-Amiri—narrated to us, from Jasrah, who said: Aisha narrated to me, saying: A Jewish woman entered upon me and said: "Indeed, the punishment of the grave is from urine." I said: "You have lied." She said: "Nay, we indeed cut the garment and the skin from it." The Messenger of Allah (ﷺ) went out to the prayer, and our voices had risen. He said: "What is this?" I informed him of what she had said. He said: "She spoke the truth." She said: From that day on, the Messenger of Allah (ﷺ) would not pray without saying at the end of the prayer: "O Allah, Lord of Jibril, Mika'il, and Israfil, protect me from the heat of the Fire and the punishment of the grave."