The Menorah was made out of a solid block of gold. All its decorations were carved out of this block and nothing was made separately and attached to the Menorah afterwards. The pasuk says Rashi highlights this fact by saying “Kaftoreha U’Pracheha Mimena Yihiyu”; it’s knobs and flowers should come from within it.
The Chasam Sofer says that the Menorah represents the light of Torah and we learn from it that no outside science or wisdom should be used to adorn the Torah. The torah has all its light within it and nothing in the outside world can enhancethis brilliant light.
With this idea he explains the gemara Megila (32) “He who holds the Sefer Torah bare (without a covering) will be buried bare (without mitzvos)”. This means that if a person considers the Torah lacking and he feels it needs the beauty of science and other wisdoms to adorn it and make it complete will himself die without mitzvos since he says this is Apikurses.
