Shmuel Bais 14:19

And HaMelech said, Is not the yad Yoav with thee in all this? And the isha answered and said, As thy nefesh liveth, adoni HaMelech, none can turn to the right or to the left from anything that adoni HaMelech hath spoken; for thy eved Yoav, he instructed me, and he put all these devarim in the peh (mouth) of thine shifchah (handmaid)