Jesus answered them, “Is it not written in your law, ‘I said, “You are gods”’? (John 10:34).
In this passage, Jesus is referring to Psalm 82:6. The Psalm verse in question is a reference to the judges of Israel who, since they exercised the divine prerogative to judge, were called “gods.” In the Psalm, God is condemning the judges of Israel for their wicked judgments and reminding them that they will face him at the ultimate judgment. In the Gospel of John, Jesus is pointing out the hypocrisy of the Jewish leaders in assuming the descriptor “god” but denying it to Jesus.