This dead dog - See the marginal reference and 2 Samuel 9:8 note.

Go over - The ravine, possibly with a stream of water 2 Samuel 17:20, which lay between them and Shimei.

Then said Abishai the son of Zeruiah unto the king,.... A sister's son of his, and a general in the army, who could not bear to hear the king abused in this manner:

why should this dead dog curse my lord the king? be suffered to do it with impunity; a "dog" he calls him, because of his vileness and baseness, and because of his impudence, and on account of his reproachful and abusive language, aptly signified by the snarling and barking of a dog; and a "dead" dog, as being useless, detestable, and abominable:

let me go over, I pray thee, and take off his head; go over the plain where David and his men were, to the hill on which Shimei was, and strike off his head with his sword; which he could easily do, and soon put an end to his cursing.

Abishai wanted to put an end to this cursing (on the expression "dead dog," see 2 Samuel 9:8). "Let me go," said he to David, "and take away his head," i.e., chop off his head. But David replied, "What have I to do with you, ye sons of Zeruiah?" Joab probably joined with Abishai. The formula "what to me and you?" signifies that a person did not wish to have anything in common with the feelings and views of another (cf. 1 Kings 17:18; Joshua 22:24; and τὶ ἐμοὶ καὶ σοί, John 2:4. For the thing itself, comp. Luke 9:52-56). "If he curses, and if Jehovah hath said to him, Curse David, who shall then say, Wherefore hast thou done so?" For יה וכי יקלּל כּי (Chethib), the Masoretes give us the Keri, יה כּי יקלּל כּה, "so let him curse, for Jehovah," etc. This thought lies at the foundation of the rendering adopted by the lxx, who have inserted, by way of explanation, καὶ ἄφετε αὐτὸν καὶ: so let him go, and so may he curse. The Vulgate is just the same: dimittite eum ut maledicat. This interpolation is taken from 2 Samuel 16:11, and, like the Keri, is nothing more than a conjecture, which was adopted simply because כּי was taken as a causal particle, and then offence was taken at וכי. But כּי signifies if, quando, in this passage, and the ו before the following וּמי introduces the apodosis.

Then said Abishai the son of Zeruiah unto the king, Why should this dead dog curse my lord the king? let me go over, I pray thee, and take off his head.

16:5-14 David bore Shimei's curses much better than Ziba's flatteries; by these he was brought to pass a wrong judgment on another, by those to pass a right judgment on himself: the world's smiles are more dangerous than its frowns. Once and again David spared Saul's life, while Saul sought his. But innocence is no defence against malice and falsehood; nor are we to think it strange, if we are charged with that which we have been most careful to keep ourselves from. It is well for us, that men are not to be our judges, but He whose judgment is according to truth. See how patient David was under this abuse. Let this remind us of Christ, who prayed for those who reviled and crucified him. A humble spirit will turn reproaches into reproofs, and get good from them, instead of being provoked by them. David the hand of God in it, and comforts himself that God would bring good out of his affliction. We may depend upon God to repay, not only our services, but our sufferings.