When Isaiah beheld the august throne of God on this memorable day, he was sorely affrighted, for he reproached himself with not having tried to turn the king away from his impious desire. Enthralled he hearkened to the hymns of praise sung by the angels, and lost in admiration he failed to join his voice with theirs. "Woe is me," he cried out, "that I was silent! Woe is me that I did not join the chorus of the angels praising God!
Had I done it, I, too, like the angels, would have become immortal, seeing I was permitted to look upon sights to behold which had brought death to other men." Then he began to excuse himself: "I am a man of unclean lips, and I dwell in the midst of people of unclean lips." At once resounded the voice of God in rebuke: "Of thyself thou art the master, and of thyself thou mayest say what thou choosest, but who gave thee the right to calumniate My children of Israel and call them 'a people of unclean lips'?"
And Isaiah heard God bid one of the seraphim touch his lips with a live coal as a punishment for having slandered Israel. Though the coal was so hot that the seraph needed tongs to hold the tongs with which he had taken the coal from the altar, the prophet yet escaped unscathed, but he learned the lesson, that it was his duty to defend Israel, not traduce him. Thenceforth the championship of his people was the mainspring of the prophet's activity, and he was rewarded by having more revelations concerning Israel and the other nations vouchsafed him than any other prophet before or after him.
Moreover God designated Isaiah to be "the prophet of consolation." Thus it happened that the very Isaiah whose early prophecies foretold the exile and the destruction of the Temple, later described and proclaimed, in plainer terms than any other prophet, the brilliant destiny in store for Israel.