Sforno on Genesis
וקומו שובו אל האיש, you will have to face the man on the strength of the gift which has preceded you. The matter is as stated in Proverbs 17,8 אבן חן השחד בעיני בעליו אל כל אשר יפנה ישכיל, “a bribe seems like charm to its owner. Wherever he turns he seems to prosper