Parsha Vayeira - Chapter 19 – Verses 34 - 38
Both of Lot's daughters got pregnant. The eldest daughter names her son Moab (“from my father") The younger names her son Ben-Ammi (“son of my clan”), a more veiled & modest reference to the situation.
It is unimaginable for us, but our Sages say that the story of the daughters of Lot was in order to extract two good sparks & this was all part of Hashem’s master plan. The two sons of the daughters, grew into two mighty nations, Moav and Amon. From Moav descended Ruth, the famous convert who was destined to become the great grandmother of King David, and ultimately of Mashiach. Rus is known as "Ima shel Malchus" (the mother of royalty). From Ammon descended Naamah, wife of King Solomon, and mother of his firstborn son and heir, Rehoboam who was the first King of House Judah.