Chabad.org — English translation + Rashi
Torah Temimah cites Menachos 29b: the construction of the Menorah was difficult for Moshe until the Holy One showed it to him with the finger (“וזה מעשה המנורה”).
English: A teaching of the school of Rabbi Yishmael: the making of the Menorah was difficult for Moshe until the Holy One, Blessed be He, showed it to him with His finger, as it is written “And this is the work of the Menorah.”
Gezerah / word “זה” — the demonstrative “this” indicates pointing with the finger, as elsewhere in Scripture.
Even for Moshe, certain mitzvot required direct Divine demonstration. The Menorah’s intricate details could not be grasped from verbal description alone.