A negress (or a youth) used to sweep the mosque. The Prophet (ﷺ) missed him, and when he asked about him the people told him that he had died. He said: Why have you not informed me ? He said: Lead me to his grave. So they led him and he prayed over him.
Sunan Abi Dawud Book 21, Hadith 115
← Previous Hadith The Messenger of Allah (ﷺ) led us in prayer over bier of a Muslim and I heard him say: O Allah, so and so, son of so and so, is in Thy protection, so guard him from the trial in the grave. (AbdurRahman in his version said: "In Thy protection and in Thy nearer presence, so guard him from the trial in the grave) and the punishment in Hell. Thou art faithful and worthy of praise. O Allah, forgive him and show him mercy. Thou art the forgiving and the merciful one." AbdurRahman said: "On the authority of Marwan ibn Janah."

Sunan Abi Dawud Book 21, Hadith 114 Next Hadith → The Messenger of Allah (ﷺ) gave the people news of death of Negus on the day on which he died, took them out to the place of prayer, drew them up in rows and said: "Allah is Most Great" four times.

Sunan Abi Dawud Book 21, Hadith 116