"A lying tongue hates those it crushes, and a flattering mouth works ruin"
It is interesting that there is a tie between lying and flattery. Solomon is trying to get us to notice the connection. He is trying to mark those who are liars by their use of flattery. We often fall under the seduction of flattery, not realizing that it is the initial step in identifying a liar. Don't get sucked into the sunshine that liars are pumping about you. It is nice to hear people talking about you in ways that you know are not true, but it will lead to ruin.
This is the Hebrew word seqer which means lie. It is that which is unreliable, deceptive.
This the Hebrew word sane which means to hate.
Notice this truth that Solomon shares about a liar: They despise the ones they are hurting. It is their way of striking back. It is their weapon.
This verse suggests there is a difference between a liar and a person who occasionally tells lies. The confirmed liar only loves themself and uses their lying as a club against those who would try and restrict their behavior. The liar is the person who believes that they are superior to the people who fall for their lies. Those people are beneath them and if they fall for these tricks, then they deserve to be crushed.
In order to keep a lie going, one must have a constant source of motivation. It is often the desire to stay out of trouble but it can also be, as Solomon is pointing out here, that the liar wants to punish or wound or hurt the other person.
This is the Hebrew word dak which means crushed or oppressed. The idea is clearly that the person is suffering because of the lies that are told.
This is the Hebrew word halaq which means smoothness, flattery. The idea is of a person who just butters up his intended victim. You hear a string of nice things about yourself that are easy to listen to and what you hope is how people perceive you. Flattery, however, always has no basis in fact. What you are being praised for is not true and you know it. This is like giving Father of the Year Awards to a father who was never home for his children. This is like hearing about how hard you work and reveling in it while you know you don't.
Solomon is trying to warn us that when we hear unfounded praise, we are being flattered and this is the beginning step of being lied to.
This is the Hebrew word midheh which means ruin. The idea is that a person is driven to a great fall. It has a conceptual connection to being crushed. It is this connection that Solomon is trying to point out so that you will not miss the fact that when someone is flattering you, they are lying to you. And if they are lying to you, they are seeking an advantage over you and want to use you and discard you. They do not have a great level of care for you.
Think this through... if a young man flatters a young lady about her looks or intelligence or something else which she knows is not true to the degree of his praise, then he is most likely seeking an advantage and it will work ruin in his heart. If a gang flatters a young man with how much he is wanted and how much he can do for the gang and how valuable he is when he knows it is not true, then he is being sucked into a liars’ club to be ruined and oppressed.
Now it is not wrong to receive praise. But legitimate praise is specific and tied to particular actions or qualities. Flattery is usually general and over the top. We just want it to be true, so we let it continue.
All flattery is too much, but one can never give or receive too much real praise.