Charles Ellicott Commentary Hebrews 12:17

"For ye know that even when he afterward desired to inherit the blessing, he was rejected; for he found no place for a change of mind [in his father,] though he sought is diligently with tears." — Hebrews 12:17 (ASV)

For you know how that afterward . . .—The meaning of the verse will be seen more clearly if one clause is placed in a parenthesis: “For you know that even when he afterward desired to inherit the blessing he was rejected (for he found no place of repentance), though he sought it earnestly with tears.” The blessing of Jacob related in Genesis 27 is here viewed (apart from all attendant circumstances) as a necessary consequence of Esau’s profane scorn of his birthright. Notwithstanding Esau’s piteous entreaty, Isaac must ratify (Genesis 27:33) the blessing which he has pronounced; though his son sought the blessing earnestly with tears (Genesis 27:38), he was rejected. He found no place of repentance; that first act (Genesis 25:33) could not be recalled, but brought with it a loss which nothing could retrieve.

(It is right to add that other interpretations of the verse have been given, which seem, however, much less probable. Thus, the last clause has been understood to mean that Esau earnestly sought repentance; and the preceding words, which we have placed in a parenthesis, that he could not bring his father to a change of purpose.)