﴿ وَٱلْخَٰمِسَةُ أَنَّ لَعْنَتَ ٱللَّهِ عَلَيْهِ إِن كَانَ مِنَ ٱلْكَٰذِبِينَ ﴾

“and the fifth time, that God’s curse be upon him if he is telling a lie.”

(And yet a fifth, invoking the curse of Allah on him) and on the fifth the man should invoke Allah's curse on himself (if he is of those who lie) about his wife having committed adultery.