He uses the plural, In the Prophets, because all the Prophets being filled with one and the same spirit, their prophecies, though different, all tended to the same end; and with whatever any one of them says, all the rest agree; as with the prophecy of Joel, All shall be taught of God. (Joel 2:23)
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).