They shall fear thee - That is, “men” shall fear thee, or thou shalt be feared, or reverenced. The idea is, that his reign would continue, or that he would be obeyed during all the time mentioned here.
As long as the sun and moon endure - literally, “With the sun, and before the moon;” that is, as long as they have the sun with them, or have it to shine upon them, and as long as they are in the presence of the moon, or have its light. In other words, they would continue to the end of time; or to the end of the world. It does not denote “eternity,” for it is not assumed in the Bible that the sun and moon will continue forever; but the idea is, that as long as the sun shall continue to shine upon the earth - as long as people shall dwell upon the earth - the kingdom would be perpetual. There would be no change of dynasty; no new empire would arise to displace and to supersede this. This would be the dynasty under which the affairs of the world would be wound up; this the kingdom which would be found at the consummation of all things. The reign of the Messiah will be the “final” reign in the earth; that under which the affairs of earth will close.
Throughout all generations - While the generations of people dwell on the earth.