Judas, a follower of Jesus, betrayed Jesus to the chief priests and the officers of the temple. Calling someone "Judas" is the equivalent of calling them a traitor.

"If they can, then you can do good, who are so accustomed to evil. If the Ethiopian can change his skin, or the leopard his spots: you also may do well, when you have learned evil." It's the notion that things cannot change their innate nature.

The people were going to stone a woman to death for adultery. Jesus stopped them and said, "He who is without sin among you, let him be the first to throw a stone at her."

Implies that one should not put what is valuable in front of those who will reject the notion that it has value and who will seek to diminish and destroy what one offers. Do not give what is holy to dogs; nor cast your pearls before swine, lest they trample them under their feet, and turn and tear you in pieces."