'Posterity' in the Bible

Sworn hath the Lord Jehovah by His holiness, That lo, days are coming upon you, And he hath taken you away with hooks, And your posterity with fish-hooks.

I have seen the Lord standing by the altar, and He saith: 'Smite the knob, and the thresholds shake, And cut them off by the head -- all of them, And their posterity with a sword I do slay, Not flee to them doth the fleer, Nor escape to them doth a fugitive.