John Gill Bible Commentary

If his children forsake my law,.... The same with the seed before mentioned, the children of the Messiah: it is not said "if he forsakes", which cannot be supposed of Christ, because he knew no sin, nor did any; which yet might be supposed of David, had he been literally meant; but not he, nor his natural children, but the spiritual seed of mystical David, are here designed, who may sin, and do sin, of which there is too much proof and evidence; and who sin not only through infirmity, but sometimes very grossly, and which sins are here expressed by various phrases: they sometimes "forsake the law of God"; do not attend to it, as they should, as the rule of their walk and conversation; are remiss in their observance of it, and obedience to it, and transgress its precepts; or his "doctrine" (h), even the doctrine of the Gospel; which may be said to be forsaken when men grow indifferent to it; go off from it in any measure, drop their profession of it, or hold it remissly, or become careless in their attendance on it: forsaking the assembling together to hear it, in some sense, is a forsaking of it; and this the Lord takes notice of, and resents, in his people: and walk not in my judgments; those laws of his house by which he judges, regulates, and governs his people; by which they are directed by him, as their Judge and Lawgiver, how to behave themselves in the church of God; and in which they are to walk, and continue in the observance of; and so to do is to walk as becomes the Gospel, and worthy of their calling; but to do otherwise is to walk disorderly; and such are cognizable by the Lord, and by his people. (h) "verbum meaum revelatum", Gejerus; "legem et doctrinam meam", Michaelis.