“The most eloquent of all the prophets, the one from whom most can be learned as to preaching, is obviously Isaiah. Isaiah was the very opposite of Amos, the shepherd and gardener. He lived at court during several reigns, and in that of Hezekiah was high in influence. He was a highly educated man, a man of refined taste, and singular literary power and skill. He enjoyed in the best sense of that now often misused term, the advantage of Culture, with all its light and its sweetness. His writings, like all the other inspired books, take their literary character from the natural endowments, educational advantages, and social condition, of the man. They exhibit an imperial imagination, controlled by a disciplined intellect and by good taste. This imagination shows itself in vivid and rapid description, as well as in imagery. The careful and loving study of Isaiah has educated many a preacher’s imagination to an extent of which he was by no means conscious, and few things are so important to an orator as the real cultivation of imagination. True, the book of Isaiah presents the poetic more often than then strictly oratorical use of this faculty. But the two shade into each other; and we also, when we become greatly excited, and our hearers with us, do naturally use in speaking such imaginative conceptions and expressions as generally belonging only to poetry.”
“In part 1 of the book of Isaiah the oratorical element very distinctly predominates – it is direct address, aiming at practical results in those who hear. Sometimes the style even sinks into quiet narrative, but more often it rises into passionate appeal. And in part 2 (from the 40th chapter on), the orator is lost in the poet. The prophet’s soul is completely carried away by imagination and passion, till we have no longer an inspired orator directly addressing us, but a rapt seer, bursting into song, pouring fourth in rhythmical strains his inspired and impassioned predictions. He is like the angel that appeared to the shepherds, whose message soon passed into song. Besides the yet higher blessings which have come to the world from the devotional and practical, the predictive and theological contents of this grand prophet’s writings, who can estimate how much he has done in training servants of God for the highest and truest forms of all religious eloquence!”
– John Broadus, Lectures on the History of Preaching (Solid Ground: 1907/2004) pp. 14-16