وعن أبي هريرة رضي الله عنه أن رسول الله صلى الله عليه وسلم قال‏:‏ ‏"‏بحسب امرئ من الشر أن يحقر المسلم‏"‏‏.‏ ‏(‏‏(‏رواه مسلم، وقد سبق قريبًا بطوله‏)‏‏)‏‏.‏

Jundub bin 'Abdullah (May Allah be pleased with him) reported

The Messenger of Allah (ﷺ) said, "Once someone said: 'By Allah! Allah will not forgive such and such (a person).' Thereupon Allah, the Exalted and the Glorious, said: 'Who is he who takes an oath in My Name that I will not grant pardon to so-and-so? I have granted pardon to so-and-so and rendered your good deeds fruitless."'[Muslim].