2-samuel 8:4

A thousand chariots - It is strange that there were a thousand chariots, and only seven hundred horsemen taken, and twenty thousand foot. But as the discomfiture appears complete, we may suppose that the chariots, being less manageable, might be more easily taken, while the horsemen might, in general, make their escape. The infantry also seem to have been surrounded, when twenty thousand of them were taken prisoners.

David houghed all the chariot horses - If he did so, it was both unreasonable and inhuman; for, as he had so complete a victory, there was no danger of these horses falling into the enemy's hands; and if he did not choose to keep them, which indeed the law would not permit, he should have killed them outright; and then the poor innocent creatures would have been put out of pain. But does the text speak of houghing horses at all? It does not. Let us hear; ויעקר דוד את כל הרכב vayeakker David eth col harecheb, And David disjointed all the chariots, except a hundred chariots which he reserved for himself. Now, this destruction of the chariots, was a matter of sound policy, and strict piety. God had censured those who trusted in chariots; piety therefore forbade David the use of them: and lest they should fall into the enemy's hands, and be again used against him, policy induced him to destroy them. The Septuagint render the words nearly as I have done, και παρελυσε Δαυιδ παντα τα ἁρματα.

He kept however one hundred; probably as a sort of baggage or forage wagons.

Seven hundred horsemen - It should be seven thousand, as in 1 Chronicles 18:4.

8:4 Seven hundred - Or, seven hundred companies of horsemen, that is, in all seven thousand; as it is 1 Chronicles 18:4 , there being ten in each company, and each ten having a ruler or captain. Houghed - - That is, cut the sinews of their legs, that they might be useless for war.