Hadith #2255 (Sunan Abi Dawud)
Book: Divorce (Kitab Al-Talaq)
Narrator(s): Aabad bin Mnswr عباد بن منصور, al-Hasan bin 'Ali al-Halwani الحسن بن علي الخلال الحلواني, ibn Abbas, Ikrama عكرمة, Yazid bin Harun يزيد بن هارون
Grade: Sahih

When the Prophet (ﷺ) ordered a man and his wife to invoke curses on each other, 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.

Source: https://parallelquran.com/hadith/sunan-abi-dawud-2255/