Aharon was a kollel fellow. He and his wife barely eked out enough to make ends meet, but Aharon felt fortunate to be able to dedicate his life to Torah. They were frugal with their money and avoided unnecessary expenses, keeping themselves on an even keel. Despite their tight budget, Aharon and his wife set aside each month a tenth of their earnings for tzedakah as ma’aser kesafim.
As Sukkos approached, expenses mounted. “We need to sit down and review our budget,” Aharon’s wife said. “We gave additional donations for the Yamim Noraim and need new clothes and extra food for Yom Tov. We’re coming to Sukkos with very little money left.”
Aharon carefully reviewed with his wife the expenses for the remainder of the month. “We are at our limit,” she said. “We can’t afford anything beyond the Yom Tov shopping.”
“What about lulav and esrog?” Aharon asked. “I could use someone else’s, but would like to buy my own!”
“Of course!” his wife replied. “But if we want to end the month without a deficit, we have no available money to buy our own. If we cut back on certain other expenditures, we could afford $50.”
“That’s not nearly enough for the kind of beautiful set I would like to buy,” said Aharon. “It would cost about $100.”
“Maybe we can use some of our ma’aser money to buy the esrog?” his wife suggested.
“I don’t know whether I can use ma’aser money to purchase a mitzvah,” said Aharon.
“Can you find out?” asked his wife. “It would make the situation much simpler.”
“I’ll ask Rabbi Dayan,” replied Aharon.
Aharon met Rabbi Dayan in the beis midrash. “Can I use my ma’aser money to purchase an esrog?” he asked. “What about to purchase a more beautiful [mehudar] one?”
“A person is not allowed to fulfill his obligations, even mitzvahs, with ma’aser money,” replied Rabbi Dayan. “Rama cites from Maharil that a person should not use his ma’aser money even for optional mitzvahs, such as sponsoring candles for the shul or purchasing kibbudim, but should give it to the poor. However, later authorities allow if the person stipulated initially that he would use the ma’aser money also for optional mitzvahs, especially if he would not do the mitzvah otherwise or if the proceeds of the mitzvah will ultimately benefit the poor.” (Y.D. and Taz 249:1; Shach 249:3; Pischei Teshuvah 249:2)
“Is an esrog considered an obligatory mitzvah or an optional one?” asked Aharon.
“Esrog is an obligation; it is also for personal use, unlike purchasing sefarim and allowing public use of them,” replied Rabbi Dayan. “However, since one does not need to purchase his own esrog and can use the communal esrog or a friend’s, some consider purchasing an esrog an optional mitzvah.” (Nachalas Shiva 8:7b; Minchas Yitzchak 8:82; B’tzel Hachochma 4:164)
What about using ma’aser for hiddur mitzvah, to buy a nicer esrog?” asked Aharon.
“The Gemara [B.K. 9b] states that one should be willing to add a third for hiddur mitzvah,” replied Rabbi Dayan. “Some allow even the initial third from ma’aser; some allow only beyond the initial third; and some don’t allow using ma’aser money at all for hiddur mitzvah.” (Hilchos Ma’aser Kesafim 14:24-26)
“What is the halacha, bottom line?” asked Aharon.
“Rav S.Z. Auerbach rules that one who is very tight on funds should not purchase an esrog from ma’aser money, but rather use someone else’s,” replied Rabbi Dayan. “However, if he designated a maximum amount that he can afford to purchase an esrog, he may add part of his ma’aser to purchase a more mehudar one. Bear in mind, though, that the ideal is to give ma’aser kesafim to the poor. You need to carefully weigh the hiddur of a beautiful esrog versus the hiddur of supporting the poor.” (Halichos Shlomo, Mo’adim 11:1)