The wonderful cohesiveness of Mormon scriptures with the words of Isaiah here appears on a level we may not have guessed, showing how much more these scriptures are intertwined than we may have supposed, the one forming a key to understanding the other.
For the endtime Ephraimites who had assimilated into the Gentiles - who are identified as the Gentiles or fullness of the Gentiles - applying Isaiah's covenant theology to their birthright role of restoring the house of Israel divides the rig.