Musannaf Ibn Abi Shayba 13:2189

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: Thawr narrated to us, from Mahfuz ibn ‘Alqama, from Abu al-Darda’, who said: Whoever swears an oath, intending by it to commit a sin, is a sinner in it, whether he is truthful or lying.