1)
Why did Avraham bow to them?
1.
Ohr ha'Chayim: He showed that he does not consider himself their king. Rather, they are more honored than himself!
2)
Why does it say "l'Am ha'Aretz, li'Venei Ches"?
1.
Ha'amek Davar: First one honors the Rabim (the people of the city), and then the esteemed among them.
