I tried making this point awhile back, but it went over people's heads. 

"Thou shalt not kill" is another commandment that Jesus interprets "rigidly" as being transgressed by anger, or saying to someone "You fool."

People conflate the moral law of Christ and the ceremonial law of Moses and these are two examples that confound the narrative of "rigid Pharisees/permissive Jesus" that are used to justify sins of the flesh.