What does Exodus 3:19 mean?

After commanding Moses and the elders of Israel to confront Pharaoh (Exodus 3:16–18), God warns that the Egyptian ruler will not be receptive. Pharaoh is also often called "king of Egypt" in Exodus, or "Pharaoh king of Egypt." According to God, the only way Pharaoh will agree to even the slightest release for Israel is if "compelled by a mighty hand." The "mighty hand" of God is mentioned later in Exodus (Exodus 6:1; 13:9; 32:11), Deuteronomy (Deuteronomy 3:24; 4:34; 5:15; 6:21; 7:8, 19; 9:26; 11:2; 26:8), and elsewhere in Scripture (e.g., 1 Kings 8:42; 2 Chronicles 6:32; Nehemiah 1:10; Psalm 136:12; Jeremiah 32:21; Ezekiel 20:33–34; 30:22; Daniel 9:15).

This mighty hand of God will include ten plagues (Exodus 7—12), concluding with the death of the firstborn sons of Egypt. Only after that will the Egyptian king allow the Hebrews to leave (Exodus 3:20). Further, upcoming verses conclude with the predictions the Jews will "plunder" the Egyptians through the items they request (Exodus 3:21–22). This prediction will be fulfilled as the liberated Jews are given jewelry and clothing by the Egyptians (Exodus 12:35–36, 41).