Question: There was an unfortunate incident when a family hosted a Sheva Berachos and served a tasty meaty meal. For dessert they brought what they thought was pareve ice cream and served it to all the guests. After the guests finished eating and returned home, the hosts were cleaning in the kitchen, and they saw that the containers of ice cream in the garbage had the words “chalavi” [“milky”] written in large letters on them, and they were shocked that they had served milky ice cream to all the guests after serving them a meaty meal. The question that arises is: Since they caused the guests to eat milky within the time frame of eating meaty, are they obligated to inform the guests so that they can do teshuvah for this?
Answer: Before answering whether one must inform them, we must clarify what prohibition was violated, was it a de’O’rasia, a derabbanan, what exactly did they do wrong? The Gemara in Chullin (105a), codified in Shulchan Aruch (Yoreh Deah 89:1), states that Chazal prohibited eating dairy products at the same meal as eating meat. This is an issur derabbanan as a matter of harchokah, as the issur de’O’raisa of basar b’chalav applies only if the meat and milk were cooked together over fire. Therefore, even if one eats meat and dairy together when they are cold, one only violates an issur derabbanan. Thus, in our case, the guests were caused to violate an issur derabbanan. The question is whether we need to inform them when they only violated an issur derabbanan.
There is a famous Nesivos HaMishpot (234, Biurim, 3) which says, that if someone transgresses an issur derabbanan b’shogeig [accidentally] no kaporah [atonement] is needed. Since no issur de’O’raisa was violated here, we can say that no kaporah—and thereby no teshuvah—is needed. Based on this principle, the Nesivos explains that in a case where someone purchased food that was forbidden miderabbanan and paid the price of kosher food for it and ate it, the seller does not need to refund the difference between the price of kosher and treif food, because the buyer is considered to have benefited as if they had eaten kosher food.
The reason for this is that with issurei de’O’raisa, the prohibition applies to the cheftza [item] itself, and therefore one who eats it even unknowingly is considered to have eaten inherently forbidden food. But regarding issurei derabbanan, the prohibition doesn't apply to the cheftza itself, but rather only to the gavra [person] upon whom the prohibition to eat falls, while the food itself remains like kosher food. Therefore, one who eats it is only considered to have transgressed that which Chazal forbade them to eat, and thus when done b’shogeg, it is not considered a transgression of divrei Chachamim. This is the explanation of the Nesivos according to HaGaon Rav Elchanan Wasserman hy”d, in his sefer Kovetz Ha’aros (8:15). He adds that the reason a shogeg needs kaporah is not simply because the person was not careful enough in general, rather, it is specifically because it is an issur cheftza, therefore, he should have been more careful. Therefore, with issurei derabbanan that are only prohibitions on the gavra, the issue of why they weren’t careful enough doesn’t apply, and therefore no kaporah is needed at all.
According to this, in our case where they transgressed an issur derabbanan b’shogeg, there is no michshol [stumbling block] here at all, and no kaporah is needed. Therefore, the one who caused this did not violate lifnei iveir, because they did not cause their fellow to stumble. This has been established as the halachah in a number of sifrei acharonim.
R' Yaakov Skoczylas shlita adds: Although some argue and take a more stringent approach, one may be lenient, especially considering that this is a matter of kavod habriyos in a case of an issur derabbanan, as it would be a great embarrassment for the Sheva Berachos hosts to have to tell everyone.
