A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
2 Kings (2 Samuel) 14:2
sa2 14:2JOAB INSTRUCTS A WOMAN OF TEKOAH. (2Sa. 14:1-21)
And Joab sent to Tekoah, and fetched thence a wise woman--The king was strongly attached to Absalom; and having now got over his sorrow for the violent death of Amnon, he was desirous of again enjoying the society of his favorite son, who had now been three long years absent. But a dread of public opinion and a regard to the public interests made him hesitate about recalling or pardoning his guilty son; and Joab, whose discerning mind perceived this struggle between parental affection and royal duty, devised a plan for relieving the scruples, and, at the same time, gratifying the wishes, of his master. Having procured a countrywoman of superior intelligence and address, he directed her to seek an audience of the king, and by soliciting his royal interposition in the settlement of a domestic grievance, convinced him that the life of a murderer might in some cases be saved. Tekoah was about twelve miles south of Jerusalem, and six south of Beth-lehem; and the design of bringing a woman from such a distance was to prevent either the petitioner being known, or the truth of her story easily investigated. Her speech was in the form of a parable--the circumstances--the language--the manner--well suited to the occasion, represented a case as like David's as it was policy to make it, so as not to be prematurely discovered. Having got the king pledged, she avowed it to be her design to satisfy the royal conscience, that in pardoning Absalom he was doing nothing more than he would have done in the case of a stranger, where there could be no imputation of partiality. The device succeeded; David traced its origin to Joab; and, secretly pleased at obtaining the judgment of that rough, but generally sound-thinking soldier, he commissioned him to repair to Geshur and bring home his exiled son.
2 Kings (2 Samuel) 14:7
sa2 14:7they shall quench my coal which is left--The life of man is compared in Scripture to a light. To quench the light of Israel (Sa2 21:17) is to destroy the king's life; to ordain a lamp for any one (Psa 132:17) is to grant him posterity; to quench a coal signifies here the extinction of this woman's only remaining hope that the name and family of her husband would be preserved. The figure is a beautiful one; a coal live, but lying under a heap of embers--all that she had to rekindle her fire--to light her lamp in Israel.
2 Kings (2 Samuel) 14:9
sa2 14:9the woman said . . . O king, the iniquity be on me--that is, the iniquity of arresting the course of justice and pardoning a homicide, whom the Goel was bound to slay wherever he might find him, unless in a city of refuge. This was exceeding the royal prerogative, and acting in the character of an absolute monarch. The woman's language refers to a common precaution taken by the Hebrew judges and magistrates, solemnly to transfer from themselves the responsibility of the blood they doomed to be shed, either to the accusers or the criminals (Sa2 1:16; Sa2 3:28); and sometimes the accusers took it upon themselves (Mat 27:25).
2 Kings (2 Samuel) 14:13
sa2 14:13Wherefore then hast thou thought such a thing against the people of God, &c.--Her argument may be made clear in the following paraphrase:--You have granted me the pardon of a son who had slain his brother, and yet you will not grant to your subjects the restoration of Absalom, whose criminality is not greater than my son's, since he killed his brother in similar circumstances of provocation. Absalom has reason to complain that he is treated by his own father more sternly and severely than the meanest subject in the realm; and the whole nation will have cause for saying that the king shows more attention to the petition of a humble woman than to the wishes and desires of a whole kingdom. The death of my son is a private loss to my family, while the preservation of Absalom is the common interest of all Israel, who now look to him as your successor on the throne.
2 Kings (2 Samuel) 14:22
sa2 14:22JOAB BRINGS ABSALOM TO JERUSALEM. (Sa2 14:22-33)
To-day thy servant knoweth that I have found grace in thy sight--Joab betrayed not a little selfishness amid his professions of joy at this act of grace to Absalom, and flattered himself that he now brought both father and son under lasting obligations. In considering this act of David, many extenuating circumstances may be urged in favor of it; the provocation given to Absalom; his being now in a country where justice could not overtake him; the risk of his imbibing a love for heathen principles and worship; the safety and interests of the Hebrew kingdom; together with the strong predilection of the Hebrew people for Absalom, as represented by the stratagem of Joab--these considerations form a plausible apology for David's grant of pardon to his bloodstained son. But, in granting this pardon, he was acting in the character of an Oriental despot rather than a constitutional king of Israel. The feelings of the father triumphed over the duty of the king, who, as the supreme magistrate, was bound to execute impartial justice on every murderer, by the express law of God (Gen 9:6; Num 35:30-31), which he had no power to dispense with (Deu 18:18; Jos 1:8; Sa1 10:25).
2 Kings (2 Samuel) 14:25
sa2 14:25But in all Israel there was none to be so much praised as Absalom for his beauty--This extraordinary popularity arose not only from his high spirit and courtly manners, but from his uncommonly handsome appearance. One distinguishing feature, seemingly an object of great admiration, was a profusion of beautiful hair. Its extraordinary luxuriance compelled him to cut it "at every year's end;" lit., "at times," "from time to time," when it was found to weigh two hundred shekels--equal to one hundred twelve ounces troy; but as "the weight was after the king's shekel," which was less than the common shekel, the rate has been reduced as low as three pounds, two ounces [BOCHART], and even less by others.
2 Kings (2 Samuel) 14:28
sa2 14:28So Absalom dwelt two full years in Jerusalem, and saw not the king's face--Whatever error David committed in authorizing the recall of Absalom, he displayed great prudence and command over his feelings afterwards--for his son was not admitted into his father's presence but was confined to his own house and the society of his own family. This slight severity was designed to bring him to sincere repentance, on perceiving that his father had not fully pardoned him, as well as to convince the people of David's abhorrence of his crime. Not being allowed to appear at court, or to adopt any state, the courtiers kept aloof; even his cousin did not deem it prudent to go into his society. For two full years his liberty was more restricted, and his life more apart from his countrymen while living in Jerusalem, than in Geshur; and he might have continued in this disgrace longer, had he not, by a violent expedient, determined (Sa2 14:30) to force his case on the attention of Joab, through whose kind and powerful influence a full reconciliation was effected between him and his father.