Isaiah 30:3, 5, 7

Therefore shall the strength of Pharaoh be your shame, and the trust in the shadow of Egypt your confusion.

They were all ashamed of a people that could not profit them, nor be an help nor profit, but a shame, and also a reproach.

For the Egyptians shall help in vain, and to no purpose: therefore have I cried concerning this, Their strength is to sit still.