Sforno - Hashem made Bnai Yisroel his "Kinyan" implying that we are the core reason of creation.
R' Bechaya - Bnai Yisroel was brought into this world from "Yesh M'ayan" thereby making us his kinyan; "Our Father" - The divine essence is within each of us like a son to a father therefore reflecting his characteristics.
Akaida - A characteristic of a "father" implies that everything in the world is for us making Bnai Yisroel his core.
