At which plague did God first protect Israel from Egypt's plagues?
According to the Exodus account, at the fourth plague, the flies, God first made a division between Israel and Egypt. The first three plagues affected both peoples equally, but at the flies He distinguished Goshen, where Israel dwelt, promising no flies there.
Les teaches that from the beginning of God's dealings with Abraham, Isaac, and Jacob, He let them know He would set Israel apart as a sanctified nation. In the Exodus, at the fourth plague—the flies—God told Pharaoh He would put a division between His people and Pharaoh's people. The first three plagues affected everyone alike, but He made a distinction between Egypt and Goshen, promising no flies in Goshen where Israel dwelt, to prove His power and His dealing with His covenant people.