Mr. Sherman sold hand-baked matzah directly to people in the community from his garage, which was stockpiled with matzah three weeks before Pesach.
“Who’s coming for the Seder?” Mr. Brand asked his wife a week before Pesach. “I need to know how much matzah to buy.”
“We should be sixteen people total,” replied Mrs. Brand. “Obviously, the children living at home; Chaim and Moshe are coming with their families, but Leah is planning to be at her in-laws’.”
“Ok, that should be three to four pounds,” Mr. Brand said. He bought four pounds.
Erev Pesach afternoon, Leah frantically called her mother. “My in-laws just told me that they got sick and suggested that we come for the end of Yom Tov, instead,” she said. “Is it still possible to come to you for the Seder?”
“I’m sorry about your in-laws,” replied Mrs. Brand, “but we’ll be happy to have you! I always cook extra, so food should not be a problem, and we’ll work out the sleeping arrangements somehow.”
“Leah just called to say that they would like to come for the Seder!” Mrs. Brand told her husband. “It seems that her in-laws are sick. Do we have enough matzah for them?”
“We should be okay,” replied Mr. Brand, “although it might a bit tight. But it’s too late to do anything about it now.”
At shul that evening, Mr. Brand saw Mr. Sherman. “Tell me, do you have any matzah left in your garage?” he asked. “Last minute, our daughter asked to come for the Seder, and we might need another box.”
“I do,” said Mr. Sherman. “You can stop by right after davening, before we begin the Seder; afterwards I don’t want to be interrupted.”
Mr. Sherman went to wish Rabbi Dayan a “Gut Yom Tov,” and asked:
“Am I allowed to get a box of matzah from Mr. Sherman now?”
“The Mishnah in Beitzah (29a-b) teaches that although commerce is prohibited on Shabbos and Yom Tov, a person can go to a vender whom he knows and take food items needed for that day, with certain limitations” (O.C. 323:1; 517:1; Shemiras Shabbos K’hilchasa 29:17-40).
“Among the limitations is that the price not be mentioned, such as to say or ask how much the pound of matzah costs” (Mishnah Berurah 323:13).
“Shulchan Aruch furthermore writes that although one can mention a number, such as ‘ten matzos,’ one should not mention a measure, such as a pound. However, Rama writes that common practice is in accordance with the lenient opinion that where the measure is mentioned simply to indicate the desired quantity, such as a pound, it is permitted. Similarly, according to the Rama, one can tell the vender: ‘Give me $10 worth of chocolate,’ since this is merely a way of indicating the quantity” (O.C. 323:4; Mishnah Berurah 323:17; Bei’ur Halachah 323 s.v. mutar).
“However, some Acharonim are stringent about this, and recommend avoiding mentioning measure or price entirely, like the Mechaber” (Mishnah Berurah 323: 20; Aruch HaShulchan 323:5).
“Nonetheless, it is prohibited to mention a sum total, such as to say: ‘I took four pounds before Yom Tov, with this I owe you five’” (ibid.).
“Furthermore, Chazal prohibited the use of weights and scales, even if the seller will not measure exactly, since this is still blatantly measuring” (O.C. 500:2; Mishnah Berurah 500:8).
“Although Chazal allowed measuring for the purpose of a mitzvah, and some allow even weighing matzah to ascertain the proper shiur,” concluded Rabbi Dayan, “this is where the measuring is needed for the mitzvah. However, here, although the matzah is needed for the mitzvah, weighing is not needed for the mitzvah itself” (O.C. 306:7; Kaf Hachaim 306:63; Shemiras Shabbos K’hilchasa 29:40).
Verdict: You may take from a vender food on Shabbos and Yom Tov, but the price should not be discussed nor a sum total, nor should you use scales. Rama allows mentioning a measure or price to indicate the quantity, but Acharonim recommend refraining even from this.
