What is the walaa' of a child born to a divorced (bā'in) mother based on the length of separation from the father?

Primary text

If the woman was divorced (bā'in) and gives birth four years after the separation, the child does not belong to the father, and his walaa' belongs to the patron of his mother. If she gives birth less than four years after the separation, the child belongs to the father, and his walaa' is transferred.