These scribes and pharisees and religious guys were always out to get Jesus. Surely if they looked hard enough they could find a way to catch Him out and make Him look bad.
Jesus spent a lot of time with the people no one else would dare to be seen with. He ate with them and went to their homes and He welcomed them into his presence. The religious leaders could not bear that kind of activity. How dare He spend time with ‘that kind of people.’
But here He takes it even further. He says now that these folks have a better chance of getting saved than the religious guys. They were so hung up with their religion that they could not see their unrighteousness. The tax collectors and prostitues knew they were sinner so they saw their need of repentance and redemption. They had proved it because the publicans and harlots had flocked to John and they had condemned John and ended up seeing him executed.
The scribes and pharisees were like the son who said he would go into the field and didn’t. The sinners are like the son who said he would not go but did.
How this must have shamed the religious guys. Jesus was saying that its not enough to tick the boxes and follow the dos and don’ts. They must be a change of heart. A lot of religious folks today need to learn that lesson as well.