Since the scribes and Pharisees sat in Moses' seat, what did Jesus tell the people to do with their teaching?

Jesus told the people to do and observe the things the scribes and Pharisees taught from Moses' seat. [23:2-3]

Why did Jesus say the people should not imitate the scribes and Pharisees' deeds?

Jesus said they should not imitate their deeds because they say things but then do not do them. [23:3]