779. How much must I pay to participate in the Mitzvah of Ner Chanukah?
There is a discussion among poskim whether the oil (or candles) used for ner Chanukah (the Chanukah lights) must belong to the person who uses them to do the mitzvah. Obviously, stolen property cannot be used, since mitzvah haba’ah b’aveirah(a mitzvah resulting from a transgression) is invalid according to most opinions. Even if the oil is obtained lawfully —for example it is borrowed— an individual is still required, according to some authorities, to own the object of the mitzvah to fulfill their obligation.
Owning an object according to halachah entails a kinyan (acquisition). Generally, akinyan meshichah (an acquisition via transfer of the object) is required; in this case, however, simply paying for the oil is considered a kinyan. So someone who borrows oil from a neighbor or host to light the menorah should pay outright for the oil. Likewise, a person who fulfills the mitzvah of ner Chanukah by participating in another’s lighting should contribute to the cost of the oil. (Household members who are included in the lighting by the head of the household, who owns the oil, are an exception.) The share of each participant should optimally be at least the value of shaveh prutah (the equivalent of the smallest halachic coin denomination, about three U.S. cents—See Halachah #563). Even though every person would arguably fulfill the mitzva with an even smaller stake in the oil, a group of people who are all participating in a single lighting should optimally use enough oil so that each one “owns” at least a prutah’s worth of the oil.