Rashi on Genesis 27:37/רש"י על בראשית כ״ז:ל״ז

1הן גביר AND BEHOLD I HAVE MADE HIM THY MASTER — This blessing is the seventh in the series of blessings which Isaac gave to Jacob (cf. w. 28. 29) and yet he (Isaac) singles it out as though it were the chief blessing? But the explanation is, he said to him (Esau): “What benefit will a blessing be to you? If you acquire property, it will belong to him, for “Behold, I have made him thy master״, and whatever a servant acquires becomes the property of his master (Genesis Rabbah 67:5).

2ולכה אפוא מה אעשה בני AND WHAT SHALL I DO NOW UNTO THEE [MY SON?] — Where here (איפה) shall I look for something that I can do for you?