Charles H. Spurgeon on Psalms 108:9

Moab is my washpot. This nation had shown no friendly spirit to the Israelites, but had continually viewed them as a detested rival, therefore they were to be subdued and made subject to David's throne. He claims by faith the victory, and regards his powerful enemy with contempt. Nor was he disappointed, for "the Moabites became David's servants and brought him gifts" (2Sa 8:2). As men wash their feet after a long journey, and so are revived, so vanquished difficulties serve to refresh us: we use Moab for a washpot. Over Edom will I cast out my shoe. It shall be as the floor upon which the bather throws his sandals, it shall lie beneath his foot, subject to his will and altogether his own. Edom was proud, but David throws his slipper at it; its capital was high, but he casts his sandal over it; it was strong, but he hurls his shoe at it as the gage of battle. He had not entered yet into its rock built fortresses, but since the Lord was with him he felt sure that he would do so. Under the leadership of the Almighty, he felt so secure of conquering even fierce Edom itself that he looks upon it as a mere slave, over which he could exult with impunity. We ought never to fear those who are defending the wrong side, for since God is not with them their wisdom is folly, their strength is weakness, and their glory is their shame. We think too much of God's foes and talk of them with too much respect. Who is this pope of Rome? His Holiness? Call him not so, but call him His Blasphemy! His Profanity! His Impudence! What are he and his cardinals, and his legates, but the image and incarnation of Antichrist, to be in due time cast with the beast and the false prophet into the lake of fire? Over Philistia will I triumph. David had done so in his youth, and he is all the more sure of doing it again. We read that "David smote the Philistines and subdued them" (2Sa 8:1), even as he hath smitten Edom and filled it with his garrisons. The enemies with whom we battled in our youth are yet alive, and we shall have more brushes with them before we die, but, blessed be God, we are by no means dismayed at the prospect, for we expect to triumph over them even more easily than aforetime.

Thy right hand shall thy people aid;

Thy faithful promise makes us strong;

We will Philistia's land invade.

And over Edom chant the song.

Through thee we shall most valiant prove,

And tread the foe beneath our feet;

Through thee our faith shall hills remove,

And small as chaff the mountains beat.