Assalamu ALaykum people!
" O you who believe! let not a group mock another group, it may be that the latter are better than the former, nor let some women mock any other women, it may be that the latter are better then the former, nor defame one another, nor insult one another by nicknames. How bad is it to insult one's brother after having faith?! "
Surah Hujaraat - Verse 11 - Glorious Quraan.