Ibn 'Abbas said, "I do not know anyone who acts by this ayat:

'Mankind! We created you from a male and a female, and made you into peoples and tribes so that you might come to know each other. The noblest among you in Allah's sight is the one with the most taqwa.' (49:13) One man says to another man, 'I am more noble than you are.' No one is nobler than another person except by taqwa."

حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ الْمُبَارَكِ، قَالَ‏:‏ حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، قَالَ‏:‏ حَدَّثَنَا عَبْدُ الْمَلِكِ، قَالَ‏:‏ حَدَّثَنَا عَطَاءٌ، عَنِ ابْنِ عَبَّاسٍ قَالَ‏:‏ لاَ أَرَى أَحَدًا يَعْمَلُ بِهَذِهِ الْآيَةِ‏:‏ ‏{‏يَا أَيُّهَا النَّاسُ إِنَّا خَلَقْنَاكُمْ مِنْ ذَكَرٍ وَأُنْثَى‏}‏ حَتَّى بَلَغَ‏:‏ ‏{‏إِنَّ أَكْرَمَكُمْ عِنْدَ اللهِ أَتْقَاكُمْ‏}‏، فَيَقُولُ الرَّجُلُ لِلرَّجُلِ‏:‏ أَنَا أَكْرَمُ مِنْكَ، فَلَيْسَ أَحَدٌ أَكْرَمَ مِنْ أَحَدٍ إِلا بِتَقْوَى اللهِ‏.‏