I will open my mouth in parables. — The quotation illustrates, much in the same way as those in 8:17, 12:17, St. Matthew’s peculiar way of dealing with the prophetic language of the Old Testament. He found the word “parable” at the opening of a Psalm (Psalms 78:2). The Psalm itself was in no sense predictive, but simply an historical survey of God’s dealings with Israel from the days of the Exodus to those of David. But the occurrence of the word was enough for him. Here was One whose form of teaching answered to that which the Psalmist had described, who might claim the Psalmist’s words as His own; and excluding, as he did, the idea of chance from all such coincidences, he could use even here the familiar formula, “that it might be fulfilled.”
A remarkable various-reading gives, “by Esaias the prophet.” It is found in the Sinaitic MS., and had been used before the time of Jerome by a heathen writer (Porphyry) as a proof of St. Matthew’s ignorance. Old as it is, however, there is no reason for receiving it as the original reading. The mistake was probably that of a transcriber, misled by the word “prophet,” and writing the name after the precedent of Matthew 8:17; Matthew 12:17. If the mistake had been St. Matthew’s, it would stand on the same footing as the substitution of Jeremiah for Zechariah in Matthew 27:9. The Psalm is assigned by the superscription to the authorship of Asaph.