1) There is no Isur Hana'ah on Ma'aser Sheni. Rashi here writes that Ma'aser Sheni which is Tahor may be used only for eating, drinking, or anointing. Rashi's source is the Mishnah in Ma'aser Sheni 2:1. The Bartenura there writes that this Din is derived from the verse (Devarim 14:26) which refers to what should be done with Ma'aser Sheni, "You shall spend the money on cattle and sheep and wine... and you shall eat there before Hash-m." This teaches that the Mitzvah of Ma'aser Sheni is that it should be eaten. There are two additional rules: (a) drinking is included in eating, and (b) anointing with oil is equivalent to drinking. Therefore, drinking the Ma'aser Sheni or using it for annointing is also considered equivalent to eating it, and is a way of fulfilling the Mitzvah of the Torah.

Therefore according to Rashi, if one used Ma'aser Sheni for lighting a candle, he did not transgress an Isur Hana'ah, but rather he negated the Torah Mitzvah of eating Ma'aser Sheni in Yerushalayim.

2) Another proof that there is no Isur Hana'ah on Ma'aser Sheni is the first Mishnah in Maseches Ma'aser Sheni. The Mishnah there states that one may not sell Ma'aser Sheni. The Bartenura writes that the reason is that it is holy, and this Mishnah follows the opinion of Rebbi Meir that "Ma'aser Mamon Gavo'ah" -- Ma'aser belongs to Hash-m and the Beis ha'Mikdash. One sees that according to the opinion that "Ma'aser Mamon Hedyot" -- Ma'aser belongs to its worldly owners -- one may sell it and we are not concerned that one is transgressing an Isur Hana'ah by using the proceeds of the sale.

1) There is a source for this in the Talmud Yerushalmi 2:1 (7a) where Rebbi Zeira says in the name of Rebbi Lazer: "From where do we know that one may not light with Ma'aser Sheni which became Tamei? The Torah teaches, 'I did not burn it when it was Tamei' (Devarim 26:14)."

The Torah Temimah (Devarim 26:69) points out that the word "Bi'arti" means to burn in fire. (The Perush ha'Rosh on the Mishnayos, at the end of Ma'aser Sheni #3, also writes that we learn from this verse that one who lights with Ma'aser Sheni Tamei before it was redeemed receives Malkus.)

However, the Torah Temimah points out that the Kesef Mishneh (Hilchos Ma'aser Sheni 3:2) indicates a source for this Din from a Diyuk in our Gemara in Yevamos, but does not mention that it is stated explicitly in the Yerusahlmi.

2) In addition, if one looks closely at the Rambam there (3:2), one notices that he learns that lighting with the Tamei Ma'aser Sheni is not a full-scale Lav, and is in fact a lighter prohibition than that of eating it. One sees this from 3:1 where the Rambam writes that one who eats Ma'aser Sheni b'Tum'ah receives Malkus. In 3:2 he writes that even if one lit the candle with Ma'aser Sheni after it became Tamei, it is forbidden unless he redeemed it, as is written, "I did not burn it when it was Tamei." We notice that in 3:2 he does not mention Malkus but merely writes that it is forbidden.

3) The Mahari Kurkus, on the above Rambam, writes that the Rambam maintains that the verse, "You may not eat in your gates" (Devarim 12:17), teaches that the chief prohibition is against eating, and reveals to us that "Lo Bi'arti Mimenu b'Tamei" refers mainly to eating, and therefore one receives Malkus only for eating.

Therefore, according to the Rambam, lighting the candle with the Ma'aser Sheni Tamei is not a full Lav with regard to Malkus but it is still forbidden by the Torah. (The Ramabam disagrees with the Rosh cited above that one receives Malkus also for lighting the candle.)

Kol Tuv,

Dovid Bloom