'Be Strong' in the Bible

Thus says the LORD of hosts: "Let your hands be strong, you who hear in these days these words from the mouth of the prophets who were in the day that the foundation of the house of the LORD of hosts was laid, even the temple, that it might be built.

It shall come to pass that, as you were a curse among the nations, house of Judah and house of Israel, so will I save you, and you shall be a blessing. Do not be afraid. Let your hands be strong."