King David was a man of God, a key ancestor of Jesus Christ, but perhaps a little "more human" than most. Along with his victories and glory came terrible troubles, usually personally-inflicted troubles, ranging from having Uriah the Hittite killed to cover up an incident of adultery with Uriah's wife Bathsheba, to the rebellion of Absalom, David's own son who led a coup that temporarily overthrew his father David as king of Israel. With the help of The Lord, David was however a survivor, not just because he was very courageous and highly-skilled on the battlefield, but also because he was a master at the fine art of bamboozling an enemy's thinking.
As he was fleeing for his life from Jerusalem with a relatively-few loyalists, David ordered a few others to remain behind and appear to be defecting to the rebel king. Those few included the priests Zadok and Abiathar, who served as David's "eyes and ears" in the capital, and more importantly, the royal advisor Hushai, who was to feign loyalty to Absalom while actually advising him in such a way that would favor David.
David sent Hushai back to Jerusalem to counter the advice of the highly-regarded, and highly-capable, Ahithophel:
"But David went up the ascent of The Mount Of Olives [shown in the photograph], weeping as he went, barefoot and with his head covered; and all the people who were with him covered their heads, and they went up, weeping as they went. And it was told David, "Ahithophel is among the conspirators with Absalom." And David said, "O Lord, I pray thee, turn the counsel of Ahithophel into foolishness."
"When David came to the summit, where God was worshiped, behold, Hushai the Archite came to meet him with his coat rent and earth upon his head. David said to him, "If you go on with me, you will be a burden to me. But if you return to the city, and say to Absalom, 'I will be your servant, O king; as I have been your father's servant in time past, so now I will be your servant,' then you will defeat for me the counsel of Ahithophel. Are not Zadok and Abiathar the priests with you there? So whatever you hear from the king's house, tell it to Zadok and Abiathar the priests. Behold, their two sons are with them there, Ahimaaz, Zadok's son, and Jonathan, Abiathar's son; and by them you shall send to me everything you hear."
"So Hushai, David's friend, came into the city, just as Absalom was entering Jerusalem" (2 Samuel 15:30-37 RSV)
Ahithophel wisely advised Absalom to attack David immediately with overwhelming force, which at that point would have almost certainly been successful in eliminating David as a military threat, even permanently as a political threat if they could have then killed David himself, but Hushai convinced Absalom to hold off the attack, which gave David time to regroup and muster his forces, thereby enabling David's eventual victory and return as king. Hushai also advised Absalom to come out of the relative safety of the palace and lead the battle against David's forces himself, a piece of baited advice that proved to be a deadly mistake for Absalom:
"Now in those days the counsel which Ahithophel gave was as if one consulted the oracle of God [see Oracles]; so was all the counsel of Ahithophel esteemed, both by David and by Absalom."
"Moreover Ahithophel said to Absalom, "Let me choose twelve thousand men, and I will set out and pursue David tonight. I will come upon him while he is weary and discouraged, and throw him into a panic; and all the people who are with him will flee. I will strike down the king only, and I will bring all the people back to you as a bride comes home to her husband. You seek the life of only one man, and all the people will be at peace." And the advice pleased Absalom and all the elders of Israel."
"Then Absalom said, "Call Hushai the Archite also, and let us hear what he has to say." And when Hushai came to Absalom, Absalom said to him, "Thus has Ahithophel spoken; shall we do as he advises? If not, you speak."
"Then Hushai said to Absalom, "This time the counsel which Ahithophel has given is not good." Hushai said moreover, "You know that your father and his men are mighty men, and that they are enraged, like a bear robbed of her cubs in the field. Besides, your father is expert in war; he will not spend the night with the people. Behold, even now he has hidden himself in one of the pits, or in some other place. And when some of the people fall at the first attack, whoever hears it will say, 'There has been a slaughter among the people who follow Absalom.' Then even the valiant man, whose heart is like the heart of a lion, will utterly melt with fear; for all Israel knows that your father is a mighty man, and that those who are with him are valiant men."
"But my counsel is that all Israel be gathered to you, from Dan to Beersheba, as the sand by the sea for multitude, and that you go to battle in person. So we shall come upon him in some place where he is to be found, and we shall light upon him as the dew falls on the ground; and of him and all the men with him not one will be left. If he withdraws into a city, then all Israel will bring ropes to that city, and we shall drag it into the valley, until not even a pebble is to be found there."
"And Absalom and all the men of Israel said, "The counsel of Hushai the Archite is better than the counsel of Ahithophel." For The Lord had ordained to defeat the good counsel of Ahithophel, so that The Lord might bring evil upon Absalom." (2 Samuel 16:23-17:14 RSV)
Fact Finder: How did Absalom die in battle against his father's forces?
2 Samuel 18:1-18