“It is sufficient evil for a man to look down on his Muslim brother.”  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ حَسْبُ امْرِئٍ مِنَ الشَّرِّ أَنْ يَحْقِرَ أَخَاهُ الْمُسْلِمَ  

He who has in his heart the weight of a mustard seed of pride shall not enter Paradise. A person (amongst his hearers) said: Verily a person loves that his dress should be fine, and his shoes should be fine. He (the Holy Prophet) remarked: Verily, Allah is Graceful and He loves Grace. Pride is disdaining the truth (out of self-conceit) and contempt for the people.  

عَنِ النَّبِيِّ ﷺ قَالَ لاَ يَدْخُلُ الْجَنَّةَ مَنْ كَانَ فِي قَلْبِهِ مِثْقَالُ ذَرَّةٍ مِنْ كِبْرٍ قَالَ رَجُلٌ إِنَّ الرَّجُلَ يُحِبُّ أَنْ يَكُونَ ثَوْبُهُ حَسَنًا وَنَعْلُهُ حَسَنَةً قَالَ إِنَّ اللَّهَ جَمِيلٌ يُحِبُّ الْجَمَالَ الْكِبْرُ بَطَرُ الْحَقِّ وَغَمْطُ النَّاسِ  

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).  

أَنَّ رَسُولَ اللَّهِ ﷺ حَدَّثَ أَنَّ رَجُلاً قَالَ وَاللَّهِ لاَ يَغْفِرُ اللَّهُ لِفُلاَنٍ وَإِنَّ اللَّهَ تَعَالَى قَالَ مَنْ ذَا الَّذِي يَتَأَلَّى عَلَىَّ أَنْ لاَ أَغْفِرَ لِفُلاَنٍ فَإِنِّي قَدْ غَفَرْتُ لِفُلاَنٍ وَأَحْبَطْتُ عَمَلَكَ أَوْ كَمَا قَالَ