ציטירנדיקער פּירוש אויף דברים 27:20

Another Midrash (Yalkut Shimoni 157) states that the words אז חללת יצועי עלה, reflect Yaakov saying to his son Reuven: “your sin will not be fully expiated until the presence on earth of the one of whom the Torah writes (Exodus 19,3) ומשה עלה אל האלו-הים, ‘and Moses ascended to G’d.’” When Moses came to Mount Eyval (Deut. 27,20) and appointed the tribe of Reuven as the first one (amongst the ones who would utter the curses) we find that the paragraph contains the words: “cursed anyone who sleeps with the wife of his father.” This is proof that by that time Reuven’s misdemeanor had finally been totally expiated.

Bahya writes. “When you mounted your father’s bed” [49:4], means, you have desecrated two beds. One is the bed of the Shekhinah that used to be on the bed and the other is my bed. Therefore, it is written, “my beds.” This means two beds, since the Shekhinah was always with Jacob. Even in bed, Jacob’s thought was on the Shekhinah. The Midrash says that Jacob said to Reuben. You will not be healed from the disgrace until Moses Our Teacher will ascend mount Ebal and will count Reuben first for the curses. That is, they will curse whoever will transgress the Torah. Moses Our Teacher will say to the tribe of Reuben that they should ascend mount Ebal and should curse. “Cursed be he who sleeps with his father’s wife” [Deut. 27:20]. This means, cursed be he who sleeps with his father’s wife. As soon as all of Israel knew that Reuben was innocent, then he was forgiven for the transgression.⁴⁷Bahya, Genesis, 49:4.