Lot's daughters - a story from Igros Moshe

My son’s Rebbe last week told the boys to look in the intro to vol. 8 of Igros Moshe for a story that relates to P’ Vayeira. I’ll save you the search – this is a wild one. A man took gravely ill with some affliction of his tongue (this apparently was in Russia). R’ Moshe visited the man and he asked everyone to leave the room so he could tell R’ Moshe privately what had happened to him. The previous week was P’ Vayeira, and the man related how he had been speaking of the daughters of Lot and how foolish and wicked they were. That night two old women came to him in a dream and introduced themselves as Lot’s daughters. The man’s words had made such an impression in the olam ha’emes that they came to set the record straight. They explained that everyone knew they were saved miraculously from Sdom by G-d. Had they chosen to do so, they could have said that their children came miraculously from G-d as well – immaculate concption. This could have been the cause of a whole new religion of avodah zarah. But instead, explained Lot’s daughters, they chose to acknowledge that their children came from their father – they deliberately named them Mo-Av and Amon to indicate that yes, they mistakenly had these children through their father, but they were not immaculately conceived or a result of any miracle. As punishment for his speaking ill the man’s tongue was afflicted, and after telling this story to R’ Moshe he passed away.