Isaias 29:12

In Isaiah: “And all these words shall be unto you as the words of a book that is sealed, which, if you shall give to a man that knoweth letters to read, he shall say, I cannot read, for it is sealed. But in that day the deaf shall hear the words of the book, and they who are in darkness and in a cloud; the eyes of the blind shall see.” Also in Jeremiah: “In the last of the days ye shall know those things.” In Daniel, moreover: “Secure the words, and seal the book until the time of consummation, until many learn, and knowledge is fulfilled, because when there shall be a dispersion they shall know all these things.” Likewise in the first Epistle of Paul to the Corinthians: “Brethren, I would not that ye should be ignorant, that all our fathers were under the cloud.” Also in the second Epistle to the Corinthians: “Their minds are blinded even unto this day, by this same veil which is taken …

4. I feel myself growing dizzy with all this, and wonder whether, in obeying you, I have not been obeying God, nor walking in the footsteps of the saints, unless it be that my too great love to you, and my unwillingness to cause you any pain, has led me astray and caused me to think of all these excuses. We started from the words of the preacher, where he says: “My son, beware of making many books.” With this I compare a saying from the Proverbs of the same Solomon, “In the multitude of words thou shalt not escape sin; but in sparing thy lips thou shalt be wise.” Here I ask whether speaking many words of whatever kind is a multitude of words (in the sense of the preacher), even if the many words a man speaks are sacred and connected with salvation. …

And, after this, wishing to refute completely from the words of the prophets all these traditions of the elders among the Jews, He brought before them a saying, from Isaiah, which in the exact words is as follows: “And the Lord said, This people draws nigh to Me with their mouth,” etc.; and, as we said before, Matthew has not written out the prophetical saying in the very words. And, if it be necessary because of its use in the Gospel to interpret it according to our ability, we will take in addition the preceding passage which is, in my judgment, noted with advantage by us for the exposition of that passage in the Gospel which was taken from the prophet. …