'Themselves' in the Bible

And many nations shall join themselves to Jehovah in that day, and shall be unto me for a people; and I will dwell in the midst of thee, and thou shalt know that Jehovah of hosts hath sent me unto thee.

And I answered the second time and said unto him, What are the two olive-branches which are beside the two golden tubes that empty the gold out of themselves?

And it shall come to pass in that day that I will make Jerusalem a burdensome stone unto all peoples: all that burden themselves with it shall certainly be wounded, and all the nations of the earth shall be assembled together against it.