سنن النسائي

Mus'ab bin Sa'd narrated that his father said: "I swore by Al-Lat and Al-'Uzza and my companions said to me: 'What a bad thing you have said! You have said something horrible.' So I went to the Messenger of Allah (ﷺ) and told him about that. He said: 'Say: La ilaha illallah wahdahu la sharika lah, lahul-mulk wa lahul-hamd wa huwa 'ala kulli shay'in qadir (There is none worthy of worship except Allah with no partner or associate; His is the Dominion, to Him be all praise, and He is able to do all things). Spit to your left three times, seek refuge with Allah from the Shaitan, and do not say that again.'"