18 He urged them to plead for mercy from the God of heaven concerning this mystery, so that he and his friends might not be executed with the rest of the wise men of Babylon.

Read Daniel 2:18 Using Other Translations

That they would desire mercies of the God of heaven concerning this secret; that Daniel and his fellows should not perish with the rest of the wise men of Babylon.
and told them to seek mercy from the God of heaven concerning this mystery, so that Daniel and his companions might not be destroyed with the rest of the wise men of Babylon.
He urged them to ask the God of heaven to show them his mercy by telling them the secret, so they would not be executed along with the other wise men of Babylon.