Why is it forbidden to cut nails on Thursday?
Question
I don’t understand why it is forbidden to cut nails on Thursday? After all, that which starts to grow on Shabbat happens by itself, so how is that different from planting, which is permitted at all times, even though if one plants on Sunday, it will come to fruition on Shabbat? And if it is indeed forbidden, is it also forbidden on Friday when the following Sunday is a holiday, and also on the eve of Rosh Hashanah and abroad on every holiday since there is a second day? It seems that it should not be so, as we do not find such a prohibition in the poskim, but again, what is the difference?
Answer
Hello,
The Mishnah Berurah (Orach Chaim 428, 6, and in the Sha'ar HaTziyon there) wrote in the name of the Eliyah Rabah that they are careful not to cut nails on Thursday because they begin to grow back on Tuesday after being cut, thus it is not considered a preparation for the honor of Shabbat as they start to grow on Shabbat. The intention here is that the Shulchan Aruch (there, section 1) states that it is a mitzvah to cut nails on Friday. Therefore, having one's nails grow back on Shabbat does not honor Shabbat. Naturally, this matter does not relate to seeds that are set to take root on Shabbat, as there is no issue of honoring Shabbat at all.
When a holiday falls on Sunday, one may cut nails on Friday without concern, even though they will begin to grow on the holiday, since this is done in honor of Shabbat (see Piskei Teshuvot there, note 51, citing responsa Shevet HaKehati, part 1, section 116), and the same applies to the eve of Rosh Hashanah and abroad on any holiday eve where one may cut nails without concern despite them growing back on the second day of the holiday, as this is done in honor of the holiday.
It should be noted that the custom of Sephardic Jews is not to be concerned with cutting nails on Thursday (Or Letziyon, part 2, chapter 47, section 4).
Sincerely,
Hillel Meir
