John had questioned Jesus' identity, and Jesus had defended John's identity. Jesus now warned his hearers who rejected John's identity and Jesus' identity.
7:29 Verses 29 and 30 do not appear in the Matthew parallel. They reveal a deep division among the people, and they set the scene for Jesus' comments that follow (vv. 31-35).
Many of the "common people,"even tax collectors, had responded to John's message and had undergone his baptism (3:12, 21). When they heard Jesus' preaching, these people responded positively. They praised God when they heard Jesus speaking highly of John because they had undergone baptism by him. Jesus' words about John vindicated their earlier decision to submit to John's baptism.
7:30 However, the Pharisees and lawyers (scribes) did not submit to John's baptism showing that they had rejected God's purpose, namely His plan of salvation for them.
7:31-32 This second group, the present generation of unbelievers, was similar to faithless Israel in the past (cf. Deut. 32:5, 20; Judg. 2:10; Ps. 78:8; 95:10; Jer. 7:29). They, too, were subject to God's wrath. They were behaving no better than fickle children who become upset when their peers refuse to cooperate with them. Jesus pictured the religious leaders as children sitting down and calling out to others to march to their tune. However, their peers would not cooperate so the religious leaders criticized them.
7:33-34 These unbelieving religious leaders did not like John because he was too much of an ascetic. He would not "dance"for them. However they did not like Jesus either. They believed He was too much of a libertine as they defined that term, too joyful. Jesus would not "weep"for them. Because John ate locusts and wild honey instead of bread and wine, the unbelieving Pharisees and lawyers accused him of having a demon. His fanatical behavior also suggested this to them. Jesus, on the other hand, took part in feasts eating and drinking freely. They accused Him of gluttony and drunkenness. The Old Testament described an Israelite who was a glutton and a drunkard as worthy of stoning (cf. Deut. 21:20). Furthermore Jesus associated with people whom the Jewish leaders regarded as apostates.
John and Jesus were both living parables. John taught the importance of repentance, and Jesus offered joy and blessing. However the Jewish religious leaders missed the points of both their messages because John and Jesus did not dance to their tunes. Jesus probably referred to Himself as the Son of Man here because this title always stresses His deity (Dan. 7:13-14). This would heighten the seriousness of the religious leaders' rejection.
7:35 Despite the rejection of the Jewish leaders, those who accept God's plan (v. 30) as John and Jesus announced it demonstrated its rightness. Their lives were testimonies to the truthfulness of what they had believed, which John and Jesus had proclaimed. Jesus stated this truth as a principle. The behavior of good children (i.e., disciples) normally points to their having wise parents (i.e., John and Jesus). John and Jesus had also behaved as good children of God and had vindicated His wisdom by their behavior.
Luke's account of these condemnatory words is fuller than Matthew's. Luke focused on the religious leaders' rejection whereas Matthew applied Jesus' words to all the unbelieving Israelites that He faced more generally.