אבן עזרא — ויבז עשו את הבכרה

Q — Why did Esav so readily despise the bechorah for a bowl of lentils?

A — Ibn Ezra's answer is striking in its simplicity and almost subversive in its consequences: Yitzchak had become poor in his old age. Though wealthy in youth (inheriting Avraham's fortune), he later lost it. So the bechorah carried no material expectation for Esav. Ibn Ezra brings six textual proofs of Yitzchak's impoverishment: (1) Yitzchak loved Esav specifically because Esav brought him food; (2) Esav wouldn't sell the bechorah for a stew if bread were plentiful; (3) Yitzchak's request "הביאה לי ציד" suggests delicacies were rare; (4) Yaakov had no fine clothes for his disguise; (5) Yaakov asks God on the way to Charan only for bread and clothing; (6) Rivkah didn't send money to Charan, so Yaakov had to work as a shepherd. The famous closing barb — "ועורי לב יחשבו כי העושר מעלה גדולה לצדיקים, והנה אליהו יוכיח" — is, per R' Profayt Duran's introduction to Ma'aseh Efod, Ibn Ezra speaking from his own life of poverty: he too remained great in Torah without wealth, and so refuses the equation of wealth with righteousness.