Ezra owned a grocery store, and before Pesach, he covered his chametz shelves and designated certain counters for kasher l’Pesach products.
On Friday afternoon, a customer, Noach, came into the store and decided to take a cake from one of the chametz shelves and buy it for dessert that night. When he came to the check-out counter, Ezra gave him a puzzled look. “We already sold our chametz,” he said. “Here’s our certificate, signed by Rabbi Dayan.”
“But it’s not Erev Pesach yet,” argued Noach. “Besides, you also sold your own chametz, yet you’re going to eat challah tonight.”
“The challah was set aside, and we intended to eat it,” Ezra replied, “but the chametz in the store was part of the mechiras chametz. We can’t violate the mechirah and sell you a cake that was already sold to a non-Jew.”
“Do you mind checking with Rabbi Dayan?” asked Noach.
Ezra called Rabbi Dayan and asked, “Can I sell chametz products in my store this afternoon?”
“Chametz this year has to be sold on Friday since Chazal prohibited transactions on Shabbos, and some say that you can’t even sell on Friday with the stipulation that the sale take effect on Shabbos [Choshen Mishpat 195:11; M.B. 306:33; Responsa R. Akiva Eiger 1:159; Ohr Sameach, Hil. Shabbos 23:12].
“There is another dispute about whether mechiras chametz should be done in the morning, as it’s done most years, or later in the day. Some Acharonim advocate that chametz be sold in the afternoon so that businesses can sell chametz for half the day [Daas Torah 444:2, Imrei Yosher 1:146].
“However, many rule that the mechirah should preferably be in the morning and stores shouldn’t sell chametz in the afternoon [Maharam Shick Orach Chayim #205].
“In practice, almost all rabbanim sell chametz in the morning but have special provisions in the contract covering chametz that will be eaten on Friday afternoon and evening and Shabbos morning. Similarly, some have a provision covering chametz that will be sold on Friday.
“These contracts can be written in a number of ways. The chametz can be sold in the morning with the stipulation that the sale will take effect just before Shabbos. Alternatively, the sale can cover only chametz that will still remain when Shabbos starts. A third option is to include all chametz in the sale but arrange for the non-Jew to allow the store to sell chametz on Friday afternoon and reduce accordingly the balance that the non-Jew will owe for the chametz [see Maharsham, Da’as Torah 444:1; Nezer HaTorah, 5768, vol. 17, pp. 210-236].
“Thus, it is not advisable for a store to sell chametz in the afternoon after the mechirah is done in the morning,” concluded Rabbi Dayan, “but a contract can be worded in a way that would permit it.”