Matthew Poole and continuators on Genesis 25:31

31 And Jacob said, sell me this day thy birthright .

(i. e.) Speedily without delay. So this Hebrew word is used 1 Sam. 2. 16. and 9. 13, 27. 2 Chron. 18. 4.

The birth-right then had divers singular priviledges, as 1. Dignity and Authority over his Brethren, Gen. 4. 7. and 27. 29, 37. and 49. 3. 2. A double portion, Deut. 21. 17. 1 Chron. 5. 1. 3. A special blessing from his Father, Gen. 27. 4. 4. The Priesthood and chief Government of the affairs of the Church in his Fathers absence or sickness; and after his death, Numb. 8. 16, 17, &c. 5. The first-born was a special Type both of Christ, who was to be a first-born, and of the Church, which is called Gods first-born, as Exod. 4. 22. and of the great priviledges of the Church, particularly of Adoption and Eternal Life. See Heb. 12. 23. And therefore he is justly called profane, Heb. 12. 16. for slighting so sacred and glorious a priviledge. Quest. 1. Could the birth-right be lost? Answ. Yes. See Gen. 4. 7. and 1 Chron. 5. 1. Quest. 2. Did Iacob well in this matter? Answ. No, because he tempted his brother to an act of profaneness and folly, and so was guilty of his sin. And though God had designed and promised this priviledge to him, yet he should have waited till God had executed his promise in his own way, as David did till God gave him possession of Sauls Kingdom, and not have anticipated God and snatched it by an irregular act of his own, as Ieroboam did the Kingdom from Rehoboam.