What Does Genesis 11:23 Mean?

After Serug became the father of Nahor, he lived 200 more years and had other sons and daughters. Serug's 200 post-fatherhood years give him a total of 230 years, continuing the rough descent from Peleg's and Reu's 239. The variations are small; the trajectory is consistent. Human lifespans in the Shemite line are moving toward the 175-200 year range of the early patriarchs and eventually toward the 120-year maximum that becomes the norm in the Mosaic period.

Two hundred years after Nahor's birth, Serug would have been alive to see his grandson Terah begin his path toward Haran from Ur. The overlap between the later genealogical figures is shrinking; the world is becoming more recognizably historical in its time-scales. The transition from the mythic longevity of the early chapters to the patriarchal lifespans of 100-175 years happens gradually across the chapters from the flood to Abram, and each genealogical entry is a small step in that transition.

Serug's other sons and daughters represent the immediate family context of the generation just before Abram's family becomes the story's focus. They are the aunts and uncles and cousins of a family that is about to be called out of Mesopotamia. The wider family remained; it was Terah's specific household that God would direct toward Canaan. The others stayed in the land between the rivers, part of the post-Babel world that the covenant patriarch would be the first to leave in response to a divine voice.