Synopsis of the Books of the Bible, by John Nelson Darby, [1857-62], at sacred-texts.com
Chapter 8 exhibits the return of Israel to their strength in God. If all the people were compromised by Achan's sin, it was needful that they should be sensibly restored to confidence, that they should be established, and consequently that they should go through whatever was necessary to their restoration. They must experience many things. Much experience of this kind would be avoided by walking in the simplicity and integrity of faith. Jacob had more of it than Abraham, and it was when unfaithful that Abraham went through the most (that is, of such experience as is really felt to exercise the heart). But God makes use of this to teach us what we are, and what He is: two things which-if we know them not-render experience necessary.
Success is now certain: but all the people must go up against this small city which, judging by human strength, might have been taken by two or three thousand men. Pride and false confidence are sharply rebuked by this. How much trouble must Joshua now take! Lay an ambush, feign to flee: all this to take a small city, and not much glory after all. It costs more pains to return into the path of blessing than it would have done to avoid the evil. But the simplicity of faith and its natural vigour can be regained no other way.
Meanwhile, the power of God is with them, and everything succeeds; although the manifestation of this power is not such as it was at Jericho. At length by God's command Joshua stretches out the spear that was in his hand toward the city. It does not appear that the ambush saw it, or that it was a concerted signal [See Note #1]. But as soon as it was stretched out, the ambush arose, entered the city, and set fire to it. It is thus that the Lord, working by His Spirit at the opportune moment produces activity in those even who may not know why. At a given time they are impelled onwards, and think they act from motives of their own, while it is the Lord who directs all their steps in harmony with what He is doing elsewhere: and thus He brings about the success of the whole affair. It is highly interesting to see the Lord thus the hidden spring of all action, giving impulse to the activity of His children, who in detail are ignorant of what it is that puts them in motion although, on the whole, the mind of God is revealed to them, even as Israel had the general orders of Joshua. When Christ stretches out the spear, all is activity to bring about the counsels of His wisdom and lead to the predetermined results of His mighty grace. May we only have faith to believe it!
We have still two other important facts to consider in this chapter. Jehovah had already shewn in the taking of Jericho that it was His might alone that gave victory, or rather that made everything fall before Israel, the prince of this world having no power against Him; and that, the gold and silver being Jehovah's, the people were not to seek the treasures of the conquered world, nor to enrich themselves with its spoils In general, however, when Israel had exterminated their enemies, they took possession of everything, as of the promised land. Now that these two great principles are established, (namely that the power of God is with His people, and that He will have holiness and consecration to Himself maintained in the camp,) Joshua takes formal possession of the whole country, as belonging to Jehovah. This is not celebrating the memorial of their salvation by the blood of the Lamb; nor is it feeding on the old corn of the heavenly land in the place of rest; where the grace and perfection of Christ and the redemption He has wrought out are peacefully remembered. The people treat the land itself as belonging of right to Jehovah, according to the strength of the spiritual might which is in activity to assert His rights, and which recognises them, although the conquest of the land is only just begun. Before Jericho (in type) they had fellowship with the cross, and with things above, without striking a blow.
Here, the conditions of the warfare being laid down, they publicly declare beforehand that it is Jehovah's land. Though Satan is still in possession of the contested land, by right it is Jehovah's. There were two actions by which Joshua verified this. He commanded the dead body of the king of Ai to be taken down from the tree as soon as the sun was down. This was the ordinance in Deu 21:22-23, "His body shall not remain all night upon the tree, but thou shalt in any wise bury him that day (for he that is hanged is accursed of God); that thy land be not defiled, which Jehovah thy God giveth thee for an inheritance." Israel's victory was complete. The curse hung over their enemies, who were also God's enemies. They were made a curse, and declared to be so. Now, according to Joshua's faith, the land was so entirely Israel's, as the gift of God, that it ought not to be defiled; he had, therefore, the dead body taken down that it should not be so in fact.
The other action was Joshua's building an altar on Mount Ebal. Having taken possession of Canaan as a consecrated land, they recognise Jehovah as the God of Israel by worshipping Him in the land. The altar was there as a witness, and as a bond between the people and Jehovah who had given them the land. The erection of this altar has been already spoken of, when considering the Book of Deuteronomy; I will not recur to it. I leave it to the reader to judge whether Joshua would have done better to set up this altar as soon as they had crossed the Jordan. Be that as it may, we do not always turn at once to God, when we enjoy that which His power has wrought. Our not doing so only proves our folly, whether it be in things connected with our joy or our safety. It was the Lord's mind here to give us the testimony of divine strength and human weakness before this public assumption of the land in His name; the practical realisation of being beyond Jordan in power and of Gilgal, brought home to them by its contrast. It is taken possession of in connection with Israel's responsibility under the law. Joshua now reads, before all the people, not only the curses attached to the violation of the law, but all that made known the ways of God in His government of the people.
It the more appears that this was not a concerted signal, but that the action had the meaning which I have here assigned to it, because Joshua drew not his hand back till they had utterly destroyed all the inhabitants of Ai; and this does not agree with the idea of a mere signal.