'Be Strong' in the Bible

Then a fourth kingdom (Rome) will be strong as iron, for iron breaks to pieces and shatters all things; and like iron which crushes things in pieces, it will break and crush all these [others].

He said, “O man, highly regarded and greatly beloved, do not be afraid. Peace be to you; take courage and be strong.” Now when he had spoken to me, I was strengthened and said, “Let my lord speak, for you have strengthened me.”

“Then the king of the South (Egypt) will be strong, along with one of his princes who will be stronger than he and have dominance over him; his domain will be a great dominion.