See sources here

The source material examines the opening verses of the Torah portion "Vayeilech" (31:1-2), focusing intensely on the phrase "Vayeilech Moshe" (And Moses went). Various Jewish commentators—including Rashi, Ramban, Ibn Ezra, and Sforno—present different interpretations of where Moses went and his motivation for doing so, questioning why the text emphasizes his physical movement just before his final address.