Jacob And Esau

Τῆς πτέρνης Ἠσαῦ ὁ Ἰακὼβ ἐπείληπτο ἐν τῷ τίκτεσθαι, τοῦτο σημαίνων διὰ τοῦ σχήματος, ὅτι ὁ νοῦς ὁ βλέπων Θεὸν καθαρότητι, τοῦτο φὰρ Ἰσραὴλ ἑρμηνεύεται, πτερνίζει τὰ πάθη τὰ γαστρίμαργα· ὅπερ ἐπ' αὐτῶν ἐκείνων τετέλεστο, ἡνίκα τὴν ἀκαρτέρητον λύτταν ὁ Ἐδὼμ ἐπεδείξατο, καὶ τῆς πρεσβυγενείας τὴν τιμὴν οἰκέτιν ἐποίσε βρώσεως. Ἅγιος Ἰσίδωρος Του Πηλουσιώτου, Βιβλίον Πρῶτον, Ἐπιστολή Ρϟβ' Λαμπετιῳ Source:  Migne PG 78.306b-c

Jacob held on to the heel of Esau at their birth, 1 which figure signifies the mind which in purity discerns God, for that is what Israel means translated, supplanting the appetite of the stomach. Which image was then fulfilled, being displayed in the unbridled hunger of Edom and the honour of the first born made a slave for food. Saint Isidore of Pelusium, Book 1, Letter 192, to Lampetius 1  Gen 25.25