 1 And in those days cometh John the Baptist preaching in the desert of Judea.  2 And saying: Do penance: for the kingdom of heaven is at hand.  3 For this is he that was spoken of by Isaias the prophet, saying: A voice of one crying in the desert, Prepare ye the way of the Lord, make straight his paths.  4 And the same John had his garment of camels’ hair, and a leathern girdle about his loins: and his meat was locusts and wild honey.
Matthew 3:Â 1-3
“Locusts” are the carob bean pods also called St. John’s bread. The pods are what the prodigal son fed the pigs. The tree must be 70 years old before it produces any locust beans.