1 sn Pharaoh’s double emphasis on “only” uses two different words and was meant to deceive. He was trying to give Moses the impression that he had finally come to his senses, and that he would let the people go. But he had no intention of letting them out.
2 sn “Death” is a metonymy that names the effect for the cause. If the locusts are left in the land it will be death to everything that grows.