The scribes and Pharisees hoped Jesus would say something wrong so that they could accuse him of breaking God's law. They did not want to learn from him. (See: [[rc://en/ta/man/jit/figs-metaphor]])
The writer speaks of the Pharisees as if they were thieves hiding by the side of a road waiting for someone to come by whom they could overpower and rob. In this case, they were waiting for Jesus to say something for which they could accuse him. Alternate translation: "waiting and hoping to accuse him" (See: [[rc://en/ta/man/jit/figs-metaphor]])