Ye which rejoice in a thing of nought, which say, Have we not taken to us horns by our own strength? That is, in your fancied strength, which is none at all, a mere nonentity.
"For I am God, (ולא איש velo ish), and no-man;
The Holy One in the midst of thee, yet do not frequent cities."
Amos 6:13Ye which rejoice in a thing of naught - In your idols: for an idol is nothing in the world.
Have we not taken to us horns - We have arrived to power and dignity by our strength. Horns were the symbols of power and authority. So Horace: -
Vina parant animos: tum pauper cornua sumet.
"Wine repairs our strength, and furnishes the poor with horns."
At such times they think themselves as great as the greatest.