Adam Clarke Bible Commentary

Then went Esau unto Ishmael - Those who are apt to take every thing by the wrong handle, and who think it was utterly impossible for Esau to do any right action, have classed his taking a daughter of Ishmael among his crimes; whereas there is nothing more plain than that he did this with a sincere desire to obey and please his parents. Having heard the pious advice which Isaac gave to Jacob, he therefore went and took a wife from the family of his grandfather Abraham, as Jacob was desired to do out of the family of his maternal uncle Laban. Mahalath, whom he took to wife, stood in the same degree of relationship to Isaac his father as Rachel did to his mother Rebekah. Esau married his father's niece; Jacob married his mother's niece. It was therefore most obviously to please his parents that Esau took this additional wife. It is supposed that Ishmael must have been dead thirteen or fourteen years before this time, and that going to Ishmael signifies only going to the family of Ishmael. If we follow the common computation, and allow that Isaac was now about one hundred and thirty-six or one hundred and thirty-seven years of age, and Jacob seventy-seven, and as Ishmael died in the one hundred and thirty-seventh year of his age, which according to the common computation was the one hundred and twenty-third of Isaac, then Ishmael must have been dead about fourteen years. But if we allow the ingenious reasoning of Mr. Skinner and Dr. Kennicott, that Jacob was at this time only fifty-seven years of age, and Isaac consequently only one hundred and seventeen, it will appear that Ishmael did not die till six years after this period; and hence with propriety it might be said, Esau went unto Ishmael, and took Mahalath the daughter of Ishmael to be his wife. See note on Gen 26:34, etc.