C. F. Keil and Franz Delitzsch on 2 Samuel 14:11

2Sa 14:11

The crafty woman was not yet satisfied with this, and sought by repeating her petition to induce the king to confirm his promise on oath, that she might bind him the more firmly. She therefore said still further: “I pray thee, let the king remember Jehovah thy God, that the avenger of blood may no more prepare destruction, and that they may not destroy my son.” The Chethib הרבּית is probably a copyist’s error for הרבות, for which the Masoretes would write הרבּת, the construct state of הרבּה, - a form of the inf. abs. which is not commonly used, and which may possibly have been chosen because הרבּה had become altogether an adverb (vid., Ewald, §240, e.). The context requires the inf. constr. הרבות: that the avenger of blood may not multiply (make much) to destroy, i.e., may not add to the destruction; and הרבּית is probably only a verbal noun used instead of the infinitive. The king immediately promised on oath that her son should not suffer the least harm.