1 YHWH said to Moses, “Behold, I have made you as God to Pharaoh; and Aaron your brother shall be your prophet. 2 You shall speak all that I command you; and Aaron your brother shall speak to Pharaoh, that he let the children of Israel go out of his land. Exodus 7:1-2WEB
This passage contains a positive command, directed toward Moses: "Thou shalt speak all that I command thee; and Aaron thy brother shall speak unto Pharaoh, that he let the children of Israel go out of his land.".
This command was fulfilled when Aaron and Moses spoke to Pharaoh and Israel in accordance with God's commands.