Exodus 6:11-13

6:11 “Go, tell Pharaoh king of Egypt that he must release the Israelites from his land.” 6:12 But Moses replied to the Lord, “If the Israelites did not listen to me, then how will Pharaoh listen to me, since I speak with difficulty?”

6:13 The Lord spoke to Moses and Aaron and gave them a charge for the Israelites and Pharaoh king of Egypt to bring the Israelites out of the land of Egypt.