وَعَنِ ابْنِ عَبَّاسٍ
أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أَمَرَ رَجُلًا حِينَ أَمَرَ الْمُتَلَاعِنَيْنِ أَنْ يَتَلَاعَنَا أَنْ يَضَعَ يَدَهُ عِنْدَ الْخَامِسَةِ عَلَى فِيهِ وَقَالَ: «إِنَّهَا مُوجِبَةٌ»
When the Prophet (sallallahu alayhi wa sallam) ordered a man and wife to invoke curses regarding one another, he ordered a man to put his hand on his mouth when he came to the fifth utterance, saying that it would be the deciding one. Nasai transmitted it.
Mishkat al-Masabih 3191, Book 14, Marriage, Hadith 236. 1 min read