Spreading the Light

A continuous fire shall burn upon the altar; it shall not go out. [Tzav 6:6]

There were two types of fire in the Sanctuary and Holy Temple: one that burned on the outer altar, and one that burned in the menora inside. 

The priest whose job it was to light the menora did so with a flame taken from the outer altar. 

This teaches an important lesson: The outer altar is symbolic of our Divine service with other people; the kindling of the menora alludes to Torah study, as it states in Proverbs, "The Torah is light." 

Thus in order to merit the Torah's light it isn't enough to concern oneself with one's own spiritual progress; the concern should be extended to others as well.

Source: Likutei Sichot Lubavitcher Rebbe