How did revelation come to the Prophet (peace and blessings of Allaah be upon him)?

Mukhtasar Sahih Al-Bukhari

How did revelation come to the Prophet (peace and blessings of Allaah be upon him)?

It is narrated on the authority of 'Umar bin Khattab (may Allah be pleased with him) that he said: I heard the Messenger of Allah (may peace be upon him) say: Whether every deed is accepted or not depends on the intention. For every person there is that which he intends. So if one's migration is for the purpose of Allah and His Messenger, then it will be considered as migration for the sake of Allah and His Messenger (peace be upon him). And if one's migration is for the purpose of worldly gain or to marry a woman, then his migration will be accepted in the same way for which he migrated.