And they shall know that I am Jehovah, when I have set a fire in Egypt, and all her helpers shall be broken.

And they have known that I am Jehovah, In My giving fire against Egypt, And broken have been all her helpers.

And they will be certain that I am the Lord, when I have put a fire in Egypt and all her helpers are broken.

And they shall know that I am the Lord, when I will have brought a fire into Egypt, and when all its helpers will have been worn away.

And they shall know that I am the Lord,.... The Egyptians shall know the Lord to be the true God, and acknowledge him to be omniscient and omnipotent, that should so exactly foretell their destruction, and accomplish it:
when I have set a fire in Egypt: a war there; the heat of battle, very devouring and consuming, as well as very grievous and terrible, as fire is. The Targum is,
"when I shall give (or set) people that are strong as fire against Egypt;''
the army of the Chaldeans:
and when all her helpers shall be destroyed; her auxiliaries, the neighbouring nations in alliance with them, before mentioned.

Destroyed - The fire that consumes nations is of God's kindling: and when he sets fire to a kingdom, all they that go about to quench the fire, shall be consumed by it.