John Calvin Commentary Isaiah 36:22

"Then came Eliakim the son of Hilkiah, that was over the household, and Shebna the scribe, and Joah, the son of Asaph, the recorder, to Hezekiah with their clothes rent, and told him the words of Rabshakeh." — Isaiah 36:22 (ASV)

Then came Eliakim. We now see that Eliakim and the other ambassadors were not silent, as if they either approved of Rabshakeh's impiety or, through dread of danger, tacitly condoned such blasphemies. For they tear their garments, and in that manner visibly show how deeply offended they are by those wicked slanders.

I except Shebna, who was lacking piety and was only driven by shame to put on mourning clothes along with others as a matter of form. It was customary among the Jews and other eastern nations, when they viewed anything with strong abhorrence, to tear their garments. For those nations, having much greater warmth of temperament than we who live in colder climates, display greater vehemence in gesture, behavior, dress, and other outward signs.

It should also be observed here that those who took no notice of the insults offered to them as private individuals, whenever they hear reproaches uttered against God, tear their garments. For those who are ready to take offense at an insult offered to them personally, where patience was needed, and who remain unmoved when they learn that God's name is dishonored, show that they lack zeal or piety.