Towards the middle of the eighth century--is, therefore, the most definite date to which we are able to assign the Book of Amos. At so great a distance the difference of a few unmarked years is invisible. It is enough that we know the moral dates--the state of national feeling, the personages alive, the great events which are behind the prophet, and the still greater which are imminent. We can see that Amos wrote in the political pride of the latter years of Jeroboam's reign, after the pestilence and eclipse of the sixties, and before the advance of Tiglath-Pileser in the last forties, of the eighth century.
A particular year is indeed offered by the title of the book, which, if not by Amos himself, must be from only a few years later:[123] _Words of Amos, which he saw in the days of Uzziah and of Jeroboam, two years before the earthquake_. This was the great earthquake of which other prophets speak as having happened in the days of Uzziah.[124] But we do not know where to place the year of the earthquake, and are as far as ever from a definite date.
The mention of the earthquake, however, introduces us to the answer of another of our questions--whether, with all its unity, the Book of Amos reveals any lines of progress, either of event or of idea, either historical or logical.
Granting the truth of the title, that Amos had his prophetic eyes opened two years before the earthquake, it will be a sign of historical progress if we find in the book itself any allusions to the earthquake. Now these are present. In the first division we find none, unless the threat of God's visitation in the form of a shaking of the land be considered as a tremor communicated to the prophet's mind from the recent upheaval. But in the second division there is an obvious reference: the last of the unavailing chastisements, with which Jehovah has chastised His people, is described as a _great overturning_.[125] And in the third division, in two passages, the judgment, which Amos has already stated will fall in the form of an invasion, is also figured in the terms of an earthquake. Nor does this exhaust the tremors which that awful convulsion had started; but throughout the second and third divisions there is a constant sense of instability, of the liftableness and breakableness of the very ground of life. Of course, as we shall see, this was due to the prophet's knowledge of the moral explosiveness of society in Israel; but he could hardly have described the results of that in the terms he has used, unless himself and his hearers had recently felt the ground quake under them, and seen whole cities topple over. If, then, Amos began to prophesy two years before the earthquake, the bulk of his book was spoken, or at least written down, after the earthquake had left all Israel trembling.[126]
This proof of progress in the book is confirmed by another feature. In the abstract given above it is easy to see that the judgments of the Lord upon Israel were of a twofold character. Some were physical--famine, drought, blight, locusts, earthquake; and some were political--battle, defeat, invasion, captivity. Now it is significant--and I do not think the point has been previously remarked--that not only are the physical represented as happening first, but that at one time the prophet seems to have understood that no others would be needed, that indeed God did not reveal to him the imminence of political disaster till He had exhausted the discipline of physical calamities. For this we have double evidence. In chapter iv. Amos reports that the Lord has sought to rouse Israel out of the moral lethargy into which their religious services have soothed them, by withholding bread and water; by blighting their orchards; by a pestilence, a thoroughly Egyptian one; and by an earthquake. But these having failed to produce repentance, God must visit the people once more: how, the prophet does not say, leaving the imminent terror unnamed, but we know that the Assyrian overthrow is meant. Now precisely parallel to this is the course of the Visions in chapter vii. The Lord caused Amos to see (whether in fancy or in fact we need not now stop to consider) the plague of locusts. It was so bad as to threaten Israel with destruction. But Amos interceded, and God answered, _It shall not be_. Similarly with a plague of drought. But then the Vision shifts from the realm of nature to that of politics. The Lord sets the plumbline to the fabric of Israel's life: this is found hopelessly bent and unstable. It must be pulled down, and the pulling down shall be political: the family of Jeroboam is to be slain, the people are to go into captivity. The next Vision, therefore, is of the End--the Final Judgment of war and defeat, which is followed only by Silence.