God brings a plague of locusts upon Egypt and Pharaoh agrees to let the Israelites go – but only with unacceptable conditions on their release (Exodus 10:1 – 10:20).
God said to Moses, “Go to Pharaoh, for I have hardened his heart and the hearts of his officials so that I may perform these signs before them so you can tell your children and grandchildren how I performed signs and miracles and made fools of the Egyptians so they would know that I am the Lord.” So Moses and Aaron went to Pharaoh and said, “This is what the God of the Hebrews says: ‘How long will you refuse to humble yourself before me? Let my people go, so that they may worship me. If you refuse to let them go, I will bring locusts into your country tomorrow. They will cover the ground so that it cannot be seen. They will devour what little you have