Isaiah 48:4-5

God had done this because His people were stubborn when it came to trusting Him. If He had not done this, they would have concluded that some idol had been responsible for the turn of events. They, like all people, resisted trust in a sovereign God, preferring rather to make their gods in their own image and so control them. People are by nature like animals, in that they often refuse to go a certain way, simply because their Master wants them to go that way. The "neck of iron" pictures unwillingness to bow in submission. The "brazen forehead" represents an opinionated person with a closed mind, or a shameless person who persists in sin.