Why the Dot Marks Lot's Arising

"On that night" (Genesis 19:33). The Holy One, blessed be He, agreed with her. When she lay with her father he did not know, and when she arose he understood. Therefore it is written, "and when she arose" (Genesis 19:33), with a dot. And he should have stood and guarded himself not to drink wine on the second night, yet he did not guard himself. But concerning the arising of the younger daughter it is not dotted, because she guarded herself so that her father would not become aware of her.