Imam Sufyaan’s letter to one of his Brothers

Imam Sufyaan once wrote in a letter to one of his Brothers:

"Beware of doing that which will spoil your deeds, and know that it is showing off that spoils a person's deeds, and if it is not showing off then it is conceitedness- for you to imagine that you are better than one of your Muslim brothers, when in reality he performs more good deeds than you do; or perhaps he stays further away from that which Allah has prohibited than you do; or perhaps he performs his deeds with purer intention that you do. And even if you are not conceited, beware of developing a love for praise. Be ever so careful not to come to love other people's praise of your good deeds, or the respect they feel for you and bestow upon you because of your good deeds. And beware of desiring that others should help you in your personal affairs just because they have become impressed by your good deeds. You surely claim (as does everyone else), after all, that you are doing good deeds only for the sake of Allah, well, then turn that claim into reality."

Biography of Imam Sufyaan ath-Thawri by Salaahud-Deen ibn Ali ibn Abdul-Maujood