John Calvin Commentary Psalms 72:16

"There shall be abundance of grain in the earth upon the top of the mountains; The fruit thereof shall shake like Lebanon: And they of the city shall flourish like grass of the earth." — Psalms 72:16 (ASV)

A handful of corn shall be in the earth upon the top of the mountains. The opinion of those who take a handful to mean a small portion appears well-founded. They think that these two circumstances indicate a rare and uncommon fertility.

Only a very small quantity of wheat—not even more than a man can hold in the palm of his hand—has been sown, and that even on the tops of the mountains, which are generally far from fruitful. Yet, so very abundant will be the increase that the ears will wave and rustle in the winds like the trees on Lebanon.

I do not know, however, whether David intended such a refined comparison between seedtime and harvest at all. His words may be considered more simply as denoting that so great will be the fertility, and so abundant the produce of wheat that the mountaintops shall yield, that it may be reaped with a full hand.

This figure portrays the great abundance of all good things that, through God's blessing, would be enjoyed under the reign of Christ.

To this is added the increase of children. Not only would the earth produce an abundance of all kinds of fruits, but the cities and towns also would be fruitful in the increase of people: And they shall go out from the city as the grass of the earth.

I have preferred translating the word Lebanon in the genitive case instead of the nominative, because the metonymy of using the name of the mountain, Lebanon, for the trees on it—a practice rejected by others—is rather harsh.