Why did Pharaoh say, "Atah Tihyeh Al Beisi, v'Al Picha Yishak Kol Ami"?
Malbim: When kings want to elevate one of their minor servants to a great authority, they do not do so at once, rather, in steps. First he makes him a ruler over 100, then over 1,000... First Pharaoh put Yosef over his house; anyone who comes will be fed through Yosef. Then (in 41:41), he made him ruler over all of Egypt.
Ha'amek Davar: "Al Beisi" refers to matters of the country, e.g. interpersonal laws. "V'Al Picha Yishak Kol Ami" refers to weapons; "Ami" refers to the army. He needed them to bring all the grain to the royal storehouses.
QUESTIONS ON RASHI
Rashi writes: "The throne (lit. chair) - An expression of sovereignty (as in Melachim I 1:37)." What is Rashi telling us?
Gur Aryeh: This cannot mean that Pharaoh insisted on retaining his chair in the literal sense; what is so great about a chair? Rather, Pharaoh emphasized that he would retain the title as king.