Do penance… Paenitentiam agite. Which word, according to the use of the scriptures and the holy fathers, does not only signify repentance and amendment of life, but also punishing past sins by fasting, and such like penitential exercises.
3:3. 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.
3:4. And the same John had his garment of camel's hair, and a leathern girdle about his loins: and his meat was locusts and wild honey.
3:5. Then went out to him Jerusalem and all Judea, and all the country about Jordan:
3:6. And were baptized by him in the Jordan, confessing their sins.
3:7. And seeing many of the Pharisees and Sadducees coming to his baptism, he said to them: Ye brood of vipers, who hath shewed you to flee from the wrath to come?
Pharisees and Sadducees… These were two sects among the Jews: of which the former were for the most part notorious hypocrites; the latter, a kind of freethinkers in matters of religion.
3:8. Bring forth therefore fruit worthy of penance.
3:9. And think not to say within yourselves, We have Abraham for our father. For I tell you that God is able of these stones to raise up children to Abraham.
3:10. For now the axe is laid to the root of the trees. Every tree therefore that doth not yield good fruit, shall be cut down, and cast into the fire.