Go and loose the sackcloth from off thy loins
Isaiah stripped and barefooted
Owing to the great importance which is attributed to clothing from the standpoint of Oriental culture and manners, anyone who appears without the upper garment is already regarded as naked and bare.
Isaiah has to lay off the garment of the preacher of repentance and of the mourner, so that only his tunic remains; and in this dress, and moreover barefooted, he has to appear in public. It is the costume of a man who had been robbed and disgraced, of a beggar, it may be, or a prisoner of war. (F. Delitzsch.)
God’s appointment magnifies mean things
The appointment of God renders those things and actions which in themselves seem mean and contemptible, momentous and useful: it stamps them with real dignity and importance, and makes them truly instructive. View the ceremonial institutions of the Old Testament, such as circumcision, abstinence from particular kinds of food and of raiment, uncleanness contracted by touching certain objects, and sprinkling the tabernacle with blood, and they appear trifling and ridiculous. Contemplate them again as the ordinances of God, infinitely wise and gracious, and you may discern their excellence and extensive utility. Look at our prophet as he is here described, and you see an odd appearance; but consider him acting by Divine commission, that he might represent to his countrymen the future naked and destitute condition to which those nations were to be reduced in whom they foolishly placed their confidence, and every circumstance acquires new consequence. (R. Macculloch.)
Isaiah’s obedience
When we are in the way of our duty we must trust God both with our credit and with our safety. (M. Henry.)
God’s purpose dignifies what might otherwise be scandalous
If the dress was scandalous, yet the design was glorious. (M. Henry.)