Adam Clarke on Genesis 33:10

Receive my present at my hand - Jacob could not be certain that he had found favor with Esau, unless the present had been received; for in accepting it Esau necessarily became his friend, according to the custom of those times, and in that country. In the eastern countries, if your present be received by your superior, you may rely on his friendship; if it be not received, you have every thing to fear. It is on this ground that Jacob was so urgent with Esau to receive his present, because he knew that after this he must treat him as a friend.