I. How corrupt their practices were. In general, they dealt treacherously every man against his brother, v. 10. It cannot be expected that he who is false to his God should be true to his friend. They had dealt treacherously with God in his tithes and offerings, and had defrauded him, and thus conscience was debauched, its bonds and cords were broken, a door was opened to all manner of injustice and dishonesty, and the bonds of relation and natural affection are broken through likewise and no difficulty made of it. Some think that the treacherous dealings here reproved are the same with those instances of oppression and extortion which we find complained of to Nehemiah about this time, Neh. v. 3-7. Therein they forgot the God of their fathers, and the covenant of their fathers, and rendered their offerings unacceptable, Isa. i. 11. But it seems rather to refer to what was amiss in their marriages, which was likewise complained of, Neh. xiii. 23. Two things they are here charged with, as very provoking to God in this matter—taking strange wives of heathen nations, and abusing and putting away the wives they had of their own nation; in both these they dealt treacherously and violated a sacred covenant; the former was in contempt of the covenant of peculiarity, the latter of the marriage-covenant.