Against a godless nation I send [Assyria], and against the people of my wrath I command him, to take spoil and seize plunder, and to tread them down like the mire of the streets. But he does not so intend, and his heart does not so think; but it is in his heart to destroy, and to cut off nations not a few … When the Lord has finished all his work on Mount Zion and on Jerusalem, he will punish the speech of the arrogant heart of the king of Assyria and the boastful look in his eyes. (Isaiah 10:6-7, 12)
That passage from Isaiah is notable most straightforward one, so perhaps we might pay it some attention for a short while. By this stage in the history of Israel, the kingdom has been split in two: ten tribes in the north; and two in the south. The northern kingdom soon descended into the worship of the gods of Canaan who had been worshipped in those lands in the past. It was not a happy story.
Throughout the Old Testament there is a strong relationship between the keeping of the Law given through Moses and the settlement of the Promised Land. Just before his death, Moses warned the people that if they turn to other gods, then they will lose the land. The only way to maintain life in the land is to obey the commandments of God, so Moses urges the people:
“Therefore choose life, that you and your offspring may live, loving the LORD your God, obeying his voice and holding fast to him, for he is your life and length of days, that you may dwell in the land that the LORD swore to your fathers, to Abraham, to Isaac, and to Jacob, to give them.” (Deuteronomy 30:18)
But they didn’t, and so the land was to be taken from the northern ten tribes. How? By means of the marauding warriors of the Assyrian empire. The strategy of this superpower was to conquer a nation, and then resettle the population elsewhere in their empire. And that is what happened to the northern kingdom. The Assyrians did not think they were doing God’s will - “he does not so intend” - but that was in fact what was happening.
The Assyrians were the means being used, and they were acting according to their own desires: “it is in his heart to destroy, and to cut off nations”. This means that they bear the guilt of their actions, and so they will face punishment. Justice is done, both to the Assyrians and also to the northern tribes. Deep stuff, but as the old hymn has it: “God moves in a mysterious way His wonders to perform”.