Jamieson, Fausset and Brown on Isaiah 36:12

12. Is it to thy master and thee that I am sent? Nay, it is to the men on the wall, to let them know (so far am I from wishing them not to hear, as you would wish), that unless they surrender, they shall be reduced to the direst extremities of famine in the siege (2Ch 32:11, explains the word here), namely, to eat their own excrements: or, connecting, "that they may eat," &c., with "sit upon the wall"; who, as they hold the wall, are knowingly exposing themselves to the direst extremities [Maurer]. Isaiah, as a faithful historian, records the filthy and blasphemous language of the Assyrians to mark aright the true character of the attack on Jerusalem.