John Gill, on Prov 15:10

Correction is grievous unto him that forsaketh the way,.... The right way, the way of God; the way of his commandments: the Vulgate Latin version is, "the way of life"; the same with the way of righteousness, which apostates, having known and walked in, turn aside from; see Pe2 2:15. And such deserve severe correction, the chastisement of a cruel one, correction in wrath and hot displeasure; which, when they have, is very disagreeable to them; they behave under it like a bullock unaccustomed to the yoke, and yet they are but dealt righteously with. Or the words may be rendered, "he has had bad discipline" or "instruction (z) that forsakes the way"; due care has not been taken of him; he has not been properly instructed, nor seasonably corrected; had he, he would not easily have departed from the way in which he should go; see Pro 22:6. The Targum is, "the discipline of an evil man causes his way to err;'' or him to err from his way; and he that hateth reproof shall die; that hates the reproof of parents, masters, and ministers of the word; as he may be said to do that neglects and rejects it, and does not act agreeably to it: and such a man, dying in impenitence and without faith in Christ, dies in his sins; and sometimes shamefully, or a shameful death, as the Septuagint and Arabic versions, or an untimely one; as well as dies the second death, an eternal one. (z) "fuit illi mala disciplina, vel castigatio", Baynus.