“So he began saying to the multitudes that went out to be baptized by him.” This event is also recorded in Matthew 3:7-10, and that record lets us know that although the “multitudes” were coming to John and he was speaking to them, part of what he said was to, and specifically applied to, the Jewish leaders, which were the Pharisees and Sadducees mentioned in Matthew 3:7 (see commentary on Matt. 3:7).
“You offspring of vipers!” The phrase, “You offspring of vipers! Who warned you to flee from the wrath to come” appears in the same context in Matthew 3:7 and Luke 3:7. Jesus also called the religious leaders a generation of vipers (Matt. 12:34; 23:33).
“wrath.” This is the wrath associated with the Day of the Lord (see commentary on Matt. 3:7 and Rev. 6:17).