Charles Ellicott Commentary 2 Samuel 14:19

"And the king said, Is the hand of Joab with thee in all this? And the woman answered and said, As thy soul liveth, my lord the king, none can turn to the right hand or to the left from aught that my lord the king hath spoken; for thy servant Joab, he bade me, and he put all these words in the mouth of thy handmaid;" — 2 Samuel 14:19 (ASV)

The hand of Joab. —The king immediately sees through the woman’s disguise and understands the stratagem. He knew Joab as “wily and politic and unscrupulous,” but we do not know why he suspected him of this particular interest in Absalom. Perhaps it was only the prosperous courtier’s interest in the heir-apparent, but Joab had probably made the same request before, so that the king recognized its source.