''Yet the chief wine butler did not remember Yosef, and he forgot him'' [Vayeishev 40:23]
This verse seems redundant, noted the Maharam of Amshinov. Why must it state that ''he forgot'' since it already informed us that ''the chief wine butler did not remember Yosef''?
The Rebbe answered: As soon as Yosef uttered his request to the chief wine butler he realized that he had sinned, as he had trusted in a human being instead of Hashem. He therefore prayed to Hashem that the butler would forget his request entirely! And, indeed, ''he forgot him''.
Source: Rabbi Yisrael Bronstein