Isaiah 19:21 in the World English Bible
The LORD will be known to Egypt, and the Egyptians will know the LORD in that day. Yes, they will worship with sacrifice and offering, and will vow a vow to the LORD, and will perform it.
Context
20 And it shall be for a sign and for a witness unto the LORD of hosts in the land of Egypt: for they shall cry unto the LORD because of the oppressors, and he shall send them a saviour, and a great one, and he shall deliver them.
21 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.
22 And the LORD shall smite Egypt: he shall smite and heal it: and they shall return even to the LORD, and he shall be intreated of them, and shall heal them.