Verse 13. And thresh - The future strength of the church employed in subduing her enemies, is here foretold. Iron - This expresses the strength of the church firm as iron, to beat down her enemies. Brass - By this figurative speech, is the strength of Zion expressed, treading underfoot, and breaking the power of her enemies in pieces. And I - I, the church. Their gain - The spoils of my conquered enemies.