The allusion to heroes and bearers of the bow shows that the pressure is caused by war. קַל בְּרַגְלָיו belong together: “He who is light in his feet.” The swift-footed will no more save his life than the rider upon a horse. נַפְשׁוֹ .esroh in Amo 2:15 belongs to both clauses. אַמִּץ לִבּוֹ, the strong in his heart, i.e., the hearty, courageous.