A Hard Diet

Αἱ ἀκρίδες, αἷς Ἰωάννης ἐτρέφετο, αὐ ζῶα εἰσιν ὧς τινες οἴονται ἀμαθῶς, κανθάροις ἀπεοικότα. Μὴ γένοιτο· ἀλλ' ἀκρέμονες βοτανῶν ἢ φυτῶν. Οὔτε δὲ πόα τίς ἐστι πάλιν τὸ μέλι ἄγριον. Ἀλλὰ μέλι ὄρειον ὑπὸ μελισσῶν ἀγρίων γινόμενον, πικρότατον ὄν, καὶ πάσῃ γεύσει πολέμιον. Δι' ὦν τὴν ὑπερβάλλουσαν κάκωσιν ἐπεδείκνυτο Ἰωάννης, οὐκ ἐνδείᾳ μόνῃ, ἀλλὰ καὶ τραχύτητι πὰσαν ὅρεξιν πικραίνων τοῦ σώματος. Ἅγιος Ἰσίδωρος Του Πηλουσιώτου, Βιβλιον Πρῶτον, Ἐπιστολή ΡΛΒ' Τιμοθεῳ Ἀναγωστῃ Source: Migne PG 78.269c

The locusts which John fed on are not creatures somewhat like beetles, as some unlearned folk think. May it not be, but grass or plants from the heights. Nor again is wild honey a herb. But it is honey of the mountains made by wild bees, and it is most bitter and inimical to everyone's taste. By which things John wondrously shows how he afflicted himself, not only by not eating, but by treating roughly and with bitterness the desires of the body Saint Isidore of Pelusium, Book 1, Letter 132, To Timotheus the Lector