Luke continued with the response of Jesus with a solemn pronouncement (καὶ ἐρεῖ λέγων ὑμῖν) that he did not know where they came from (Οὐκ οἶδα πόθεν ἐστέ). They were to go away from him (ἀπόστητε ἀπ’ ἐμοῦ), since they were all evildoers, workers of evil (πάντες ἐργάται ἀδικίας). This verse is somewhat similar to Matthew, chapter 7:23, from the Sermon on the Mount, perhaps a Q source. Jesus was going to declare to them that he never knew them, because they were evildoers. Just as David had told the evildoers to depart in Psalm 6:13, Jesus wanted these evildoers to leave him alone. Who were these evil doers? They seem like friendly disciples of Jesus. What evil had they done to make them unworthy on the final judgment day? The answer was not clear. Would you consider yourself an evil doer?
This citation of John seems to be a response to an unasked question, although it is similar to Matthew, chapter 3:11, Mark, chapter 1:7, and John, chapter 1:26, where there was an explicit question. Luke seemed closer to Mark, as he indicated that John answered all of the people (ἀπεκρίνατο λέγων πᾶσιν ὁ Ἰωάνης). He said that he baptized them with water (Ἐγὼ μὲν ὕδατι βαπτίζω ὑμᾶς). However, one more powerful than him was coming (ἔρχεται δὲ ὁ ἰσχυρότερός μου). John was not worthy (οὗ οὐκ εἰμὶ ἱκανὸς) to untie the thong or the strap of his sandals (λῦσαι τὸν ἱμάντα τῶν ὑποδημάτων αὐτοῦ). John the Baptist said that he was anticipating a messianic figure greater than himself. He clearly baptized in water. However, after him there would be a messianic one more powerful than him. Matthew had John unfit to carry the sandal of Jesus rather than untie the sandal. Mark, John, and Luke here had John speak about being unfit to untie the tong or strap of his sandals. John the Baptist saw himself as subservient or unworthy as compared to the Messiah to come.