Matthew 8:12

8:12 but the sons of the kingdom will be thrown out into the outer darkness, where there will be weeping and gnashing of teeth.” ¹ 

Matthew 25:30

25:30 And throw that worthless slave into the outer darkness, where there will be weeping and gnashing of teeth.’

Matthew 22:13

22:13 Then the king said to his attendants, ‘Tie him up hand and foot and throw him into the outer darkness, where there will be weeping and gnashing of teeth!’

[8:12]  ¹ sn Weeping and gnashing of teeth is a figure for remorse and trauma, which occurs here because of exclusion from God’s promise.