Our Lord Jesus, having proved himself able to save, here shows himself as willing as he is able. We suppose the prophet Isaiah to say something of himself in these verses, engaging and encouraging himself to go on in his work as a prophet, notwithstanding the many hardships he met with, not doubting but that God would stand by him and strengthen him; but, like David, he speaks of himself as a type of Christ, who is here prophesied of and promised to be the Saviour.