6. The writings of Joel bear the full impress of culture in a prophetic school. His Hebrew is of the purest kind; his style is easy, flowing, elegant, and adorned with magnificent imagery; and for vividness and power of description he is not surpassed by any of the prophets. The immediate occasion of his prophecies is a double plague of drought and locusts, which has already invaded the land, and whose desolating progress he describes in poetic strains of matchless elegance and power. He summons the people of all classes to repentance, and promises, upon this condition, not only the restoration of the land to its former fruitfulness, but also the outpouring of God's Spirit upon all flesh, the triumph of the covenant people over all their foes, and an era of universal holiness and peace. In this respect he is a model for all the prophets that come after him. They all with one accord look forward beyond the calamities of the present time, and the heavier impending calamities which they are commissioned to foretell in the near future, to the glory of the latter days, when Zion shall be made triumphant over all her foes, and the whole earth shall be given her for her inheritance. The apostle Peter, in his address on the day of Pentecost, quotes a remarkable prophecy of Joel (2:28-32, compared with Acts 2:16-21). The opinion of some commentators, that under the figure of locusts are represented simply hostile armies, must be regarded as forced and unnatural. More probable is the opinion of Henderson and others, that the prophet uses an actual invasion of the land by locusts as the type of a more formidable invasion of foreign foes. But there does not seem to be any valid reason for departing from the simple interpretation above given. III. AMOS. 7. Amos prophesied "concerning Israel in the days of Uzziah king of Judah, and in the days of Jeroboam son of Joash king of Israel, two years before the earthquake" (1:1). The time of this earthquake, which is simply mentioned by Zechariah (14:5) as occurring in Uzziah's reign, cannot be determined. We only know that Amos must have prophesied somewhere during the last part of the reign of Jeroboam II., when he was contemporary with Uzziah. Amos was thus contemporary with Hosea, and was a considerable number of years earlier than Isaiah, who began to prophesy near the close of Uzziah's long reign of fifty-two years. The very specific date "two years before the earthquake" indicates that his whole mission to Israel was executed within a single year, perhaps within a few months. It seems to have been after his return to Judah, when at least two years had elapsed, that he collected his prophecies and put them into their present form.