'Abd Allah (bin Mas’ud) said "We were in the mosque on the night of a Friday, suddenly a man from the Ansar entered the mosque". And said "If a man finds a man along with wife and declares (about her adultery) you will flog him. Or if he kills you, you will kill him or if keeps silence he will keep silence in anger. I swear by Allaah, I shall ask the Apostle of Allaahﷺ about it". On the next day he came to the Apostle of Allaahﷺ and said "If a man finds a man along with wife and declares (about her adultery) you will flog him. Or if he kills you, you will kill him or if keeps silence he will keep silence in anger". He said "O Allaah, disclose". He kept on praying until the verses regarding invoking curses (li’an) came down "As for those who accuse their wives but have no witnesses except themselves". So, the man was first involved in this trial among the people. He and his wife came to the Apostle of Allaahﷺ. They invoked curses on each other. The man bore witness before Allaah four times that the thing he said was indeed true. He then invoked curse of Allaah on him for the fifth time if he was a liar. She then wanted to invoke curses of Allaah on him. The Prophet ﷺ said "Do not do that. Bust she refused and did so (ie, invoked curses). When they returned he said "Perhaps she will give birth to a black child with curly hair.