2 Samuel 4:3 (KJV)

And when Saul's son heard that Abner was dead in Hebron, his hands were feeble, and all the Israelites were troubled.

And Saul's son had two men that were captains of bands: the name of the one was Baanah, and the name of the other Rechab, the sons of Rimmon a Beerothite, of the children of Benjamin: (for Beeroth also was reckoned to Benjamin.

And Jonathan, Saul's son, had a son that was lame of his feet. He was five years old when the tidings came of Saul and Jonathan out of Jezreel, and his nurse took him up, and fled: and it came to pass, as she made haste to flee, that he fell, and became lame. And his name was Mephibosheth.

And the sons of Rimmon the Beerothite, Rechab and Baanah, went, and came about the heat of the day to the house of Ishbosheth, who lay on a bed at noon.

And they came thither into the midst of the house, as though they would have fetched wheat; and they smote him under the fifth rib: and Rechab and Baanah his brother escaped.

For when they came into the house, he lay on his bed in his bedchamber, and they smote him, and slew him, and beheaded him, and took his head, and gat them away through the plain all night.

And they brought the head of Ishbosheth unto David to Hebron, and said to the king, Behold the head of Ishbosheth the son of Saul thine enemy, which sought thy life; and the LORD hath avenged my lord the king this day of Saul, and of his seed.