Menorah and seven branches of knowledge
Question
Where does the Gemarrah list the seven branches of wisdom as related to the seven branches of the menorah in the beis hamikdash?
Answer
Shalom!
Thank you for your question.
There is indeed a teaching that the seven branches of the Menorah represent the seven disciplines of grammar, rhetoric, logic, arithmetic, music, geometry, and astronomy, symbolizing that all knowledge must be centered around the middle stem, which represents the Torah and spirituality.
The source for this teaching is not Talmudic, but can be found in the commentary of the Abarbanel to Parshat Teruma, in Rabbeinu Bechaya to Parshat Behalotecha and in the Techelet Mordechai to Parhsat Teruma. It is also alluded to in the commentary of the Meiri to Mishlei Chapter 9.
It is also worth noting that the Midrash Rabba, Bamidbar 15:7, compares the seven lamps of the Menorah to the seven planets in the solar system which illuminate the nighttime sky.