IT IS FORBIDDEN TO BECOME FRUSTRATED IN REGARD TO THE MERCY OF ALLAH(SAHIH HADITH MUSLIM)
Friday, May 2nd, 2008Chapter# 37, Book 32, Number 6350:
Jundub reported that Allah’s Messenger (may peace be upon him) 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 his deeds (who took an oath that I would not grant pardon to him).