In these verses, the Gentiles seem to have a kind character, even humble, as they carry members of the house of Israel in their arms, nourish them, and bow to them. But Jacob’s reworking shows a different side:

Wherefore, they that fight against Zion and the covenant people of the Lord shall lick up the dust of their feet; and the people of the Lord shall not be ashamed. For the people of the Lord are they who wait for him; for they still wait for the coming of the Messiah. (2 Nephi 6:13)

Jacob interprets the dust-lickers as those who fight against Zion. It is possible he gets this from the similar language to how God cursed the serpent in Eden that it would eat dust all its life. Eating dust is a metaphor for sampling and consuming the gross filthy stuff that isn’t nourishing.

I think that the Isaiah verses describe a mixed set of behaviors—some of the Gentiles helping the house of Israel, and some others of the Gentiles fighting against Zion and ending up licking the dust off their feet.

A very interesting thing I noticed in Isaiah’s verses that I hadn’t seen before is that there is a mutual feeding going on, but the quality is not the same going each way. The Gentiles are nursing the house of Israel (mothers milk = nourishing), but licking the dust of the feet of Israel (gross, filthy, dirty = not nourishing).  The dust-lickers have perverted taste.

In what ways does that image describe reality? If we teach Christianity and the restored gospel, but then get excited about other philosophies and nature worship or some other –isms, that’s an unequal exchange.  Or, if we try to teach the gospel and write books on it, but all anyone ever wants from is the fiction we’ve written, then there’s some dust-licking going on there too. 

I think there lesson for us in these verses is we need to think carefully about the quality of what we nourish our minds and spirits with. Are we getting a good daily diet of milk and meat of the gospel, or are we eating dust?