8 Hear, my son, your father’s instruction
And do not forsake your mother’s teaching;
It is wise of a person to listen to the council learned by another. If a person can learn from the experience of those who care about them they can keep from having to learn the hard way; which is first-hand.
9 Indeed, they are a graceful wreath to your head
And ornaments about your neck.
Those who follow wisdom add beauty and honor to their lives, 3:2 adds length of life and peace to these attributes.
10 My son, if sinners entice you,
Do not consent.
Entice is defined as "attract or tempt by offering pleasure or advantage". In this case the enticing is at all costs from theft to murder.
11 If they say, “Come with us,
Let us lie in wait for blood,
Let us ambush the innocent without cause;
12 Let us swallow them alive like Sheol,
Even whole, as those who go down to the pit;
A crude and accurate exposure of the enticement mentioned in verse 10. While the one enticing often will use sweet words on the lips, the writer here is exposing it for what it truly is. In the world of business people have often justified stealing from others as long as those people don't know it. They then entice others to do the same (as they have with us). Apart from my experience you don't have to look far to see it. Insurance companies that take the money of the innocent only to use loop-holes to get out of paying a claim needed later. Advertisers will entice you with sex, money, power, etc. basically they will do anything to get your attention and have you cast your lot in with them. "swallow them alive like Sheol" They do it all shamelessly.
13 We will find all kinds of precious wealth,
We will fill our houses with spoil;
An example of what they offer. Many people have come to me in our business telling me I should charge more, when I ask them why, they usually give a variation of the above proverb. Some think I'm being stupid for not and answer my question as to why with a simple "because you can". Because we work for many businesses I have caused some friction by not consenting to their actions. Some businesses it's been exposing greed, some it's been exposing flat out sinful businesses (strip clubs, illegal drug stores, etc.)
14 Throw in your lot with us,
We shall all have one purse,”
Misery loves company. Sinners love company in sin. How often have your "friends" tried to entice you to do something you knew was wrong. Have you ever tried to entice someone else to do something you know you shouldn't have encouraged them to do? I have. "Throw in your lot with us" "We shall all have one purse" both have a similar offer of fellowship which is often enticing, but this particular fellowship is calling one to invest in evil and therefore share the spoils of evil. It's a fellowship of darkness. Gangs often entice young men who have not the Light this way.
15 My son, do not walk in the way with them.
Keep your feet from their path,
16 For their feet run to evil
And they hasten to shed blood.
17 Indeed, it is useless to spread the baited net
In the sight of any bird;
Verse 15 is an urge to keep from walking the same path of evil, verse 16 exposes that path as one that runs to evil and hurries to shed blood. Verse 16 is exposing the reason for the warning of verse 15. Verse 17 is pointing out that even the birds have enough wisdom when they see such a trap to stay away. We are being urged to recognize the trap and be at least as wise as the birds and stay away.
18 But they lie in wait for their own blood;
They ambush their own lives.
19 So are the ways of everyone who gains by violence;
It takes away the life of its possessors.
The biggest losers are not the victims of the crime but rather the perpetrator in the crime. The consequences to him are far worse than that of his victim. This actually makes them less prudent than birds.
7 Do not be deceived, God is not mocked; for whatever a man sows, this he will also reap. 8 For the one who sows to his own flesh will from the flesh reap corruption, but the one who sows to the Spirit will from the Spirit reap eternal life. - Galatians 6:7-8
See also Isaiah 17:14. Contrast also Proverbs 28:16 which shows the benefit to the person who hates unjust gain.