'Curse' in the Bible

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.

And the king said, What have I to do with you, ye sons of Zeruiah? Because he curseth, and because Jehovah hath said unto him, Curse David; who then shall say, Wherefore hast thou done so?

And David said to Abishai, and to all his servants, Behold, my son, who came forth from my bowels, seeketh my life: how much more may this Benjamite now do it ? let him alone, and let him curse; for Jehovah hath bidden him.