Musnad Ahmad 2:219

Yazid narrated to us, Yahya bin Sa'id informed us, that Muhammad bin Ibrahim informed him that he heard Alqamah bin Waqqas al-Laythi saying that he heard Umar bin al-Khattab while he was addressing the people, and he was saying: I heard the Messenger of Allah, peace and blessings of Allah be upon him, saying: "Actions are only by intentions, and every person shall have only what he intended. So, whoever’s migration was to Allah and His Messenger, then his migration is to Allah and His Messenger. And whoever’s migration was for a worldly gain he seeks, or a woman he marries, then his migration is to what he migrated for."