This portion of Torah dictates the mitzvah of kindling the menorah. Lighting the menorah in the Sanctuary, lighting the Chanukah candles and lighting the Shabbos candles are all important mitzvos.
Lighting a candle is symbolic. If you light a candle to provide light for yourself, others may benefit from the light, too. It cannot be confined. On the other hand, if you light a candle for others, you, too, can benefit from the light.
This should characterize all our actions. We should not do things that are so restrictive that others cannot benefit from them, and we should realize that when we do something for others, it is not true altruism, because we, too, will benefit from the act.