Charles Ellicott Commentary Genesis 25:26

"And after that came forth his brother, and his hand had hold on Esau`s heel. And his name was called Jacob. And Isaac was threescore years old when she bare them." — Genesis 25:26 (ASV)

His hand took hold on Esau’s heel. —Usually there is a considerable interval—an hour or more—between the birth of twins; but here Jacob appeared without delay, following immediately upon his brother. This is expressed by the metaphorical phrase that his hand had hold on Esau’s heel—that is, there was absolutely no interval between them. Though very rare, yet similar cases have been chronicled from time to time.

His name was called Jacob. —The name signifies one who follows at another’s heels. It was Esau who first ascribed a bad meaning to it (Genesis 27:36), and this bad sense has been riveted to it by Jacob’s own unworthy conduct. It is constantly so used even in the Bible.

Thus in Hosea 12:3 —a passage quoted in defence of a literal explanation of the metaphor in this verse by those who are acquainted only with the English Version—the Hebrew has, he Jacobed, literally, heeled —that is, he overreached, and got the better by cunning of —his brother in the womb. This is the very meaning ascribed to the name by Esau, and in Jeremiah 9:4 and elsewhere; but it is not well rendered by our word supplant, which contains a different metaphor, the planta being the sole of the foot; whereas to be at a person’s heel is to be his determined pursuer, and one who on overtaking throws him down.