Albert Barnes Commentary Nahum 3:12

"All thy fortresses shall be [like] fig-trees with the first-ripe figs: if they be shaken, they fall into the mouth of the eater." — Nahum 3:12 (ASV)

All thy strong-holds shall be like fig trees, with the first ripe figs - Hanging from them; eagerly sought after, to be consumed. Being ripe, they are ready to fall at once; if they be shaken; it needs but the tremulous motion, as when trees wave in the wind, they shall even fall into the mouth of the eater, not costing even the slight pains of picking them from the ground. So easy is their destruction on the part of God, though it cost more pains to the Babylonians. At the end of the world it shall be yet more fulfilled (Revelation 6:13), for then God will use no human instrument, but put forth only His own Almightiness; and all strong-holds of man’s pride, moral or spiritual, shall, of themselves, melt away.