Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: "A man goes out with his religion with him, then returns with nothing of it left. He goes to a person who has no power to benefit or harm either him or himself, and swears to him by Allah: 'You are a liar and a sinner.' So he returns without having obtained anything of his need, while Allah has become angry with him because of it (the false oath)."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 8530