Well, we’ve seen that King David does not always get things right, and that point is underlined as chapter 16 begins.
Ziba, the servant of Mephibosheth (who was Jonathan’s son), and who David had made manager of Mephibosheth’s estate, was not satisfied being the manager. He wanted to own it. So he met David while David was fleeing Absalom and give him supplies, which ingratiated him to David. And when David asked where Mephibosheth was, he told him that Mephibosheth had joined with Absalom. This was an out and out lie, but David bought it, and he gave all of Mephibosheth’s property to Ziba. David will come to regret this.
Next, David wisely restrains himself when Shimei attacks him with curses, rocks and dirt. Of course Shimei was wrong about David unjustly overthrowing Saul, but he knew that he was not a blameless man.
And then Hushai comes to Absalom, offering his services. Remember, though, that Hushai was a spy from David.
Next, Absalom asks Ahithophel what his next move should be, and Ahithophel gives him horrible, despicable advice. He tells Absalom to have sex with his father, David’s concubines, and do it so that all of Israel will know about it. This is, of course, a fulfillment of the curse that God put on David for what he did with Bathsheba.
So much dishonesty and conniving in chapter 16, and it is matched in 17, culminating in the suicide of Ahithophel, when his advice is rejected and he knows that his time is up.
Dishonesty, lust, murder, power. These things generally do not make a good recipe, and the lives of David and the people of Israel are certainly prime examples of the tragic consequences of ignoring God’s laws.