What is the 430 years counted from?
The 430 years is counted from Haran. The context contrasts this with four hundred years from the time Ishmael is sent out, when Isaac becomes the prime object of affection and everything revolves around him. So the starting point for the 430-year period is Haran, not Isaac's fifth year.
Les explains that the 430 years are counted from Haran. He contrasts that reckoning with the 400 years counted from the time Ishmael is sent out, at which point Isaac becomes the prime object of affection, because everything now revolves around him. The discussion raises the question of whether one starts from Haran or from when Isaac was five years old, but the stated reckoning is 430 years from Haran.