In Numbers 22 we hear the story about what happened when the Israelites complained against Moses and against God. Instead of trusting God, they said negative words! God sent poisonous snakes into the camp as a punishment for their sin. When they realized they were wrong, they asked Moses to pray for them. God gave them a way to be healed. He put the punishment for their sin up on a pole. When they looked at it, they didn't die.