Allah's Messenger (sallallahu alaihi wasallam) said: "Look at those who stand at a lower level than you but don't look at those who stand at a higher level than you, for this would make the favours (conferred upon you by Allah) insignificant (in your eyes)."

[Sahih Muslim, Vol. 4, Book Pertaining to Piety & Softening of Hearts, Hadith No. 7070]