What did God tell Moses He would do to Israel when He was angry?
According to the account, God in His anger told Moses He was ready to destroy the entire nation of Israel, wiping them off the map, and then begin again with Moses. He did not immediately carry it out; Moses interceded, and God spared Israel on the basis of mercy.
Les explains that God had every right in His righteousness to literally wipe Israel off the face of the map. The Word says He was hot in His anger. He told Moses, in so many words, “I’m going to destroy them all,” and He told Moses He would start over with him again. But Moses fell on his face before God and pleaded with Him, nearly thirty days, to spare the people, so the Egyptians could not say their God destroyed them in the wilderness. God spared Israel on the basis of mercy. Les cites John Darby’s thought that God withdrew into His sovereignty, and in His sovereignty poured out mercy. This pattern recurred throughout Israel’s history: when they failed God and went into idolatry, God withdrew into His sovereignty and poured out mercy.