Thou didst drove out the heathen - The Canaanites were as a bad tree planted in a good soil, and bringing forth bad fruit with great luxuriance. God plucked up this bad tree from the roots, and in its place planted the Hebrews as a good tree, a good vine, and caused them to take root, and fill the land.
How thou didst drive out the heathen with thy hand - The word rendered “heathen” means simply nations without necessarily conveying the idea of paganism, as that word is now understood. It means the nations, to wit, of the land of Canaan, or the Canaanites; and as these nations were in fact idolaters, or strangers to the true religion, the word came in time to have that idea attached to it. It is in that sense that we use the term now, though the word nations would accurately express the meaning of the original. The word rendered “drive out” - ירשׁ yârash - means properly to take, seize, or take possession of; and then, in the form here used (Hiphil), it means to cause to possess; to give possession of; and then, to take possession of, to drive out of a possession, to dispossess, to disinherit. The meaning here is, he dispossessed them of their country; he disinherited them. This, the psalmist says, God had done “by his hand;” that is, it was by his own power.
And plantedst them - That is, planted his people - the children of Israel. He put them in the place of those whom he had disinherited or dispossessed. The word is properly applicable to a tree, but it is also used with reference to a nation, and means that he assigned them a fixed and permanent residence. Thus we say in English, “to plant a colony.” Compare Amos 9:15; Jeremiah 24:6; Jeremiah 32:41; Psalm 80:8; 2 Samuel 7:10.
How thou didst afflict the people - That is, the people of the land of Canaan; the nations that dwelt there. The word means to bring evil or calamity upon anyone.
And cast them out - The word used here may be taken in the sense of sending out or expelling, as in Genesis 3:23; 1 Kings 9:7 - and then it would be applicable to the Canaanites, as meaning that God had expelled or driven them out - as it is understood by our translators; or it may be used to denote the sending out of shoots or branches by a tree or vine, as in Psalm 80:11; Jeremiah 17:8; Ezekiel 17:6-7 - and then it would refer here to the Israelites, and would mean that God caused them to increase; multiplied them; spread them over the land, as a vine spreads, Psalm 80:8-11. The parallelism here clearly demands the latter interpretation. So it is understood by Luther, DeWette, Tholuck, and Prof. Alexander.