And the LORD shall be known to Egypt, and the Egyptians shall know the LORD in that day, and shall do sacrifice and oblation; yea, they shall vow a vow unto the LORD, and perform {it}.
Yahweh will be known to Egypt, and the Egyptians will know Yahweh in that day. Yes, they will worship with sacrifice and offering, and will vow a vow to Yahweh, and will perform it.