'Be Strong' in the Bible

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

And it shall come to pass that, as ye were a curse among the nations, O house of Judah and house of Israel, so will I save you, and ye shall be a blessing. Fear not, but let your hands be strong.