New Defender's Study Bible Notes
25:19 generations of Isaac. Genesis 25:19a terminates the long record kept by Isaac, which apparently began at Genesis 11:27 where Terah’s record left off. Much of the narrative of Genesis 12–22, of course, would have been told Isaac by his father Abraham. At this point (Genesis 25:19b), it seems that Jacob took over the task, finally terminating his toledoth at Genesis 37:2.