10-20. When thou comest nigh unto a city to fight against it, then proclaim peace unto it—An important principle is here introduced into the war law of Israel regarding the people they fought against and the cities they besieged. With "the cities of those people which God doth give thee" in Canaan, it was to be a war of utter extermination (De 20:17, 18). But when on a just occasion, they went against other nations, they were first to make a proclamation of peace, which if allowed by a surrender, the people would become dependent [De 20:11], and in the relation of tributaries the conquered nations would receive the highest blessings from alliance with the chosen people; they would be brought to the knowledge of Israel's God and of Israel's worship, as well as a participation of Israel's privileges. But if the besieged city refused to capitulate and be taken, a universal massacre was to be made of the males while the women and children were to be preserved and kindly treated (De 20:13, 14). By this means a provision was made for a friendly and useful connection being established between the captors and the captives; and Israel, even through her conquests, would prove a blessing to the nations.

     18-27. the children of Israel smote them not—The moral character of the Gibeonites' stratagem was bad. The princes of the congregation did not vindicate either the expediency or the lawfulness of the connection they had formed; but they felt the solemn obligations of their oath; and, although the popular clamor was loud against them, caused either by disappointment at losing the spoils of Gibeon, or by displeasure at the apparent breach of the divine commandment, they determined to adhere to their pledge, "because they had sworn by the Lord God of Israel." The Israelitish princes acted conscientiously; they felt themselves bound by their solemn promise; but to prevent the disastrous consequences of their imprudent haste, they resolved to degrade the Gibeonites to a servile condition as a means of preventing their people from being ensnared into idolatry, and thus acted up, as they thought, to the true spirit and end of the law.