John Gill Commentary Genesis 27:37

"And Isaac answered and said unto Esau, Behold, I have made him thy lord, and all his brethren have I given to him for servants. And with grain and new wine have I sustained him. And what then shall I do for thee, my son?" — Genesis 27:37 (ASV)

And Isaac answered and said to Esau

Giving an account of the blessing he had bestowed upon his brother: behold, I have made him your lord ; the lord of his posterity, who would be subdued and become tributary to his seed:

and all his brethren I have given to him for servants ; the Edomites, who sprung from his brother Esau, who, according to this prophetic blessing, became servants to David, who was a son of Jacob's, (See Gill on Genesis 27:29);

and with corn and wine I have sustained him ; promised him a fruitful country, the land of Canaan, abounding with all good things, particularly with corn and wine, which are put for all the rest:

and what shall I do now to you, my son ? what remains? what can be bestowed upon you? there is nothing left; dominion over others, even over all nations, yea, over yourself and your posterity, and plenty of all good things, are given already to Jacob; what is there to be done for you, or you can expect?