Mishkat al-Masabih 75

Abu Hurayra reported: I heard the Messenger of God say, “People will continue questioning one another until it is said, ‘God created creation, so who created God?’ When they say that, say: ‘God is One; God, the Self-Sufficient. He neither begets nor is begotten, and none is His equal.’ Then let him spit to his left three times and seek refuge in God from Satan.” Abu Dawud transmitted it.