KJV: And the disciples were astonished at his words. But Jesus answereth again, and saith unto them, Children, how hard is it for them that trust in riches to enter into the kingdom of God!

NIV: The disciples were amazed at his words. But Jesus said again, “Children, how hard it is to enter the kingdom of God!

ESV: And the disciples were amazed at his words. But Jesus said to them again, “Children, how difficult it is to enter the kingdom of God!

CSB: The disciples were astonished at his words. Again Jesus said to them, “Children, how hard it is to enter the kingdom of God!

Internal evidence

The added phrase softens Jesus’ statement from the “rich” to those who “trust in their riches.”

UBS gives the omission of the words a B rating.