Musar su Genesi 46:8

Why did the Midrash have to mention that Abraham's name was Abraham? Why did the Midrash have to mention that Jacob was called Israel? Both of these facts are recorded in the Torah explicitly! Another difficulty is that since the patriarchs are viewed as a group, why are Jacob and Isaac not also called Abraham? Neither, for that matter, do we find Abraham called Isaac? Why does the Midrash quote the verse from the beginning of the book of Exodus instead of quoting from Parshat Vayigash in which the descent of all the family of Jacob to Egypt is recorded? We find the identical wording to that in Exodus in Genesis 46,8. From that verse it is easier to conclude that Isaac was called Israel than from the verse in Exodus 1,1, since the stress in that latter verse is on the words את יעקב באו, they had come with Jacob. Rabbi Natan's statement emphasizing its profound meaning is puzzling. What profundity is there in his statement?