Which oil is best for lighting the Hanukkah candles?

Question: Is there a preference for a particular oil for lighting the Hanukkah candles?

Answer:

Yes.

According to the Ben Ish Chai, olive oil is the choicest way to perform the mitzvah.

What about oil that was under a bed?

The Ben Ish Chai writes that Hanukkah or Shabbat candles should not be lit with edible oil that was placed under a bed.

The reason he gives is that, according to halachic tradition, food placed under a bed may be spiritually harmed.

Since the oil has become unfit for eating, it should not be used for a mitzvah, in line with the principle of “offer it to your governor”: what we dedicate to a mitzvah should be dignified.

On the other hand, if it is bitter oil that is not fit for eating, the Ben Ish Chai permits using it.