'Know' in the Bible

For, behold, I will shake mine hand upon them, and they shall be a spoil to their servants: and ye shall know that the LORD of hosts hath sent me.

And many nations shall be joined to the LORD in that day, and shall be my people: and I will dwell in the midst of thee, and thou shalt know that the LORD of hosts hath sent me unto thee.

The hands of Zerubbabel have laid the foundation of this house; his hands shall also finish it; and thou shalt know that the LORD of hosts hath sent me unto you.

And they that are far off shall come and build in the temple of the LORD, and ye shall know that the LORD of hosts hath sent me unto you. And this shall come to pass, if ye will diligently obey the voice of the LORD your God.