It was narrated from 'Imran bin Husain that the Prophet said: There is no vow to commit an act of disobedience, and no vow concerning that which the son of Adam does not possess.
It was narrated from Thabit bin Ad-Dahhak, that the Messenger of Allah said: Whoever swears by a religion other than Islam, telling a lie, will be as he said, and whoever kills himself with something, he will be punished with it in the Hereafter, and there is no vow concerning that which a man does not possess.