It was narrated that ‘Alqamah said: ‘Abdullah said:

Whilst we were sitting in the mosque on the night before Friday, a man among the Ansar said: By Allah, if a man finds a man with his wife and he speaks (of it), he will certainly be flogged, and if he kills him, he will certainly be killed, but if he keeps quiet, he is keeping quiet when he is feeling frustrated and angry. By Allah, in the morning, I shall certainly go to the Messenger of Allah (ﷺ). When morning came, he went to the Messenger of Allah (ﷺ) and said: O Messenger of Allah, if a man finds a man with his wife and he speaks (of it), he will certainly be flogged, and if he kills him, he will certainly be killed, but if he keeps quiet, he is keeping quiet when he is feeling frustrated and angry. He started saying: O Allah, clarify, O Allah clarify. Then the verse of li'an was revealed: “And for those who accuse their wives, but have no witnesses except themselves..." (an-Noor 24:6).