9 I refer to these passages, not to convict the evangelists of falsification— a charge worthy only of impious men like Celsus, Porphyry, and Julian— but to bring home to my critics their own want of knowledge, and to gain from them such consideration that they may concede to me in the case of a simple letter what, whether they like it or not, they will have to concede to the Apostles in the Holy Scriptures. Mark, the disciple of Peter, begins his gospel thus:— “The beginning of the gospel of Jesus Christ, as it is written in the prophet Isaiah: Behold I send my messenger before your face which shall prepare your way before you.
The voice of one crying in the wilderness, Prepare ye the way of the Lord, make his paths straight.” This quotation is made up from two prophets, Malachi that is to say and Isaiah. For the first part: “Behold I send my messenger before your face which shall prepare your way before you,” occurs at the close of Malachi. But the second part: “The voice of one crying, etc.,” we read in Isaiah. On what grounds then has Mark in the very beginning of his book set the words: “As it is written in the prophet Isaiah, Behold I send my messenger,” when, as we have said, it is not written in Isaiah at all, but in Malachi the last of the twelve prophets?
Let ignorant presumption solve this nice question if it can, and I will ask pardon for being in the wrong. The same Mark brings before us the Saviour thus addressing the Pharisees: “Have ye never read what David did when he had need and was an hungred, he and they that were with him, how he went into the house of God in the days of Abiathar the highpriest, and did eat the show-bread which is not lawful to eat but for the priests?” Now let us turn to the books of Samuel, or, as they are commonly called, of Kings, and we shall find there that the highpriest's name was not Abiathar but Ahimelech, the same that was afterwards put to death with the rest of the priests by Doeg at the command of Saul. Let us pass on now to the apostle Paul who writes thus to the Corinthians: “For had they known it, they would not have crucified the Lord of glory.
But, as it is written, Eye has not seen nor ear heard, neither have entered into the heart of man, the things which God has prepared for them that love Him.” Some writers on this passage betake themselves to the ravings of the apocryphal books and assert that the quotation comes from the Revelation of Elijah; whereas the truth is that it is found in Isaiah according to the Hebrew text: “Since the beginning of the world men have not heard nor perceived by the ear, neither has the eye seen, O God, beside you what you have prepared for them that wait for you.” The Septuagint has rendered the words quite differently: “Since the beginning of the world we have not heard, neither have our eyes seen any God beside you and your true works, and you will show mercy to them that wait for you.”
We see then from what place the quotation is taken and yet the apostle has not rendered his original word for word, but, using a paraphrase, he has given the sense in different terms. In his epistle to the Romans the same apostle quotes these words from Isaiah: “Behold I lay in Sion a stumbling-stone and rock of offense,” a rendering which is at variance with the Greek version yet agrees with the original Hebrew. The Septuagint gives an opposite meaning, “that you fall not on a stumblingstone nor on a rock of offense.”
The apostle Peter agrees with Paul and the Hebrew, writing: “but to them that do not believe, a stone of stumbling and a rock of offense.” From all these passages it is clear that the apostles and evangelists in translating the old testament scriptures have sought to give the meaning rather than the words, and that they have not greatly cared to preserve forms or constructions, so long as they could make clear the subject to the understanding.
Source: Letters (New Advent)