Sunan At-Tirmidhi

Abdullah bin Abi Qatadah narrated from his father that:The Prophet was brought a (deceased) man to perform Salat over. So the Prophet said: ""Pray for your companion; for indeed he had a debt upon him."" Abu Qatadah said: ""It shall be upon me."" So the Messenger of Allah said: ""To pay it off?"" (He said: ""To pay it off."") So he performed the prayer for him