He shall break in pieces - He crushes or destroys the great. He is not intimidated by their wealth, their rank, or their number.
Without number - Margin, more correctly, “searching out.” That is, he does it without the protracted process of a judicial investigation. The Hebrew word used here (חקר chêqer) means properly “a searching out,” “an examination”; and the meaning here is, that there is no need of his going into a protracted investigation into the lives of wicked people before he brings them to punishment. He sees them at once; knows all their conduct, and may proceed against them without delay. Hence, it is that he comes often in such a sudden manner, and cuts them off. A human tribunal is under a necessity of examining witnesses and of attending to all the palliating circumstances, before it can pronounce a sentence on an offender. But it is not so with God. He judges at once and directly, and comes forth therefore in a sudden manner to cut down the guilty.
And set others in their stead - Place others in the situation which they now occupy. That is, he can with the utmost case make entire revolutions among people.