Jundub رضي الله عنه narrated: “Allah’s Messenger صلى الله عليه وسلم stated that a person said: Allah would not forgive such and such (person). Thereupon Allah the Exalted and Glorious, said: Who is he who adjures about Me that I would not grant pardon to so and so; I have granted pardon to so and so and blotted out your deeds (meaning the one who took an oath that I would not grant pardon to him).”

Sahih Muslim