Hadees Related to Intention (Niyat)

'Umar ibnil Khattab Radiyallahu 'anhu narrated: I heard Rasulullah Sallallahu 'alaihi wasallam saying: Verily the reward of deeds depend upon intentions; and' indeed every man shall receive what he intended for. Thus, he whose migration was for ALLAH and His Messenger, so his migration will be considered for ALLAH and His Messenger. He whose migration was towards the world or to be married to some woman, his migration will be considered to be for what he migrated for. (Sahih-Bukhari)