Proverbs 20:20

20 If someone curses their father or mother, their lamp will be snuffed out in pitch darkness.

Read Proverbs 20:20 Using Other Translations

Whoso curseth his father or his mother, his lamp shall be put out in obscure darkness.
If one curses his father or his mother, his lamp will be put out in utter darkness.
If you insult your father or mother, your light will be snuffed out in total darkness.