When ye have transgressed the covenant of the LORD your God, which he commanded you, and have gone and served other gods, and bowed yourselves to them; then shall the anger of the LORD be kindled against you, and ye shall perish quickly from off the good land which he hath given unto you. Ye shall perish quickly from off the good land - The following note from Mr. John Trapp is very judicious: "This judgment Joshua inculcates Joshua 23:13, Joshua 23:15, and here, because he knew it would be a very grievous thing to them to forego so goodly a land, so lately gotten, and so short a while enjoyed. In the beginning of a speech τα ηθη, the milder affections, suit best; but towards the end τα παθη, passionate and piercing passages; according to the orator. This rule Joshua observes, being Ex utroque Caesar; no less an orator than a warrior."
In all this exhortation we see how closely Joshua copies the example of his great master Moses. See Leviticus 26:7, Leviticus 26:8, Leviticus 26:14, etc.; Deuteronomy 28:7; Deuteronomy 32:30. He was tenderly concerned for the welfare of the people, and with a deeply affected heart he spoke to their hearts. No people ever were more fairly and fully warned, and no people profited less by it. The threatenings pronounced here were accomplished in the Babylonish captivity, but more fully in their general dispersion since the crucifixion of our Lord. And should not every Christian fear when he reads, If God spared not the natural branches, take heed that he spare not thee? Surely a worldly, carnal, and godless Christian has no more reason to expect indulgence from the justice of God than a profligate Jew. We have a goodly land, but the justice of God can decree a captivity from it, or a state of bondage in it. The privileges that are abused are thereby forfeited. And this is as applicable to the individual as to the whole system.
Commentary on the Bible, by Adam Clarke [1831].