Talmud - Mo'ed Katan 19a מועד קטן י״ט א׳

And one may spin sky-blue wool for his ritual fringes on his thigh, but not in the ordinary manner with a spindle, as this procedure must be performed in an altered manner on the intermediate days of a Festival.

GEMARA: The Sages taught the following baraita: A person may write phylacteries and mezuzot for himself and spin sky-blue wool for his fringes on his thigh. And for others he may do these things as a favor, but not for payment. This is the statement of Rabbi Meir. Rabbi Yehuda says: If he initially made them for himself, he may employ artifice, sell his own and then go back and write new ones for himself. Rabbi Yosei says: He may write and sell them in his usual manner, in the amount that is enough to provide for his livelihood.

Rav ruled for Rav Ḥananel, and some say it was Rabba bar bar Ḥana who ruled for Rav Ḥananel: The halakha is that one may write and sell them in his usual manner, in the amount that is enough to provide for his livelihood.

§ The mishna taught: And one may spin sky-blue wool for his ritual fringes on his thigh. The Sages taught a baraita: A person may spin sky-blue wool for his ritual fringes on his thigh, but not with a stone, which can be used to form a small spindle and ease the spinning process; this is the statement of Rabbi Eliezer. But the Rabbis say: One may spin the sky-blue wool even with a stone. Rabbi Yehuda said in the name of Rabbi Eliezer: It is permitted with a stone, but not with a spindle. And the Rabbis say: One may spin this wool with either a stone or a spindle.

Rav Yehuda said that Shmuel said, and similarly Rabbi Ḥiyya bar Abba said that Rabbi Yoḥanan said: The halakha is that one may spin the sky-blue wool for fringes on the intermediate days of a Festival, both with a stone and with a spindle, owing to the importance of the mitzva of ritual fringes. And similarly the halakha is: One may write phylacteries and mezuzot on the intermediate days of a Festival in his usual manner and sell enough to provide for his livelihood.

MISHNA: One who buries his deceased relative three days before a pilgrimage Festival has the decree of the seven-day period of mourning, i.e., the halakhot and prohibitions associated with that period, nullified for him by the Festival. He is not required to complete this seven-day mourning period after the Festival. If one buries his deceased relative eight days before a pilgrimage Festival, then the decree of thirty days is nullified for him. The restrictions that ordinarily apply during this thirty-day mourning period no longer apply after the Festival.

This is because the Sages said a principle with regard to this issue: Shabbat counts as one of the days of mourning, although one may not mourn on it and it does not interrupt the mourning period, which continues after Shabbat. The pilgrimage Festivals, on the other hand, interrupt the mourning period, so that if one began mourning before such a Festival, then the mourning period is canceled by the Festival. They do not, however, count. If one did not begin mourning before the Festival, or if his relative died during the Festival, then he is required to complete his mourning period afterward, as the days of the Festival do not count toward the requisite days of mourning.

Rabbi Eliezer says: From the time that the Temple was destroyed, Shavuot is like Shabbat, because nowadays the days following Shavuot are not treated like Festival days. When the Temple stood, many of the Festival’s offerings that could not be sacrificed on Shavuot itself would be sacrificed during the six days following the Festival. Nowadays, however, when offerings are no longer sacrificed, Shavuot lasts for only one day in Eretz Yisrael, and therefore it is treated like Shabbat with regard to mourning: It counts as one of the days of mourning, but does not interrupt the period of mourning.

Rabban Gamliel says: Even Rosh HaShana and Yom Kippur are considered like the pilgrimage Festivals, in that they interrupt the mourning period but are not counted toward the days of mourning. And the Rabbis say: The halakha is neither in accordance with the statement of Rabbi Eliezer nor in accordance with the statement of Rabban Gamliel. Rather, with regard to mourning, Shavuot is treated like the other pilgrimage Festivals, whereas Rosh HaShana and Yom Kippur are treated like Shabbat.

GEMARA: With regard to the mishna’s statement that the seven- and thirty-day periods of mourning are nullified, Rav said: The decree, meaning the main prohibitions of the period, was nullified, but the days of mourning themselves were not entirely nullified. Instead, these periods of mourning remain to some degree. And so said Rav Huna: The decree was nullified, but the days of mourning themselves were not nullified. And Rav Sheshet said: Even the days of mourning were also nullified.

The Gemara asks: What is the reason that the days themselves were not nullified? The Gemara explains: It is so that if one observed eight days of mourning before the Festival, so that the prohibition against hair cutting was nullified before the Festival, but for whatever reason he did not cut his hair on the eve of the Festival, he is prohibited from cutting his hair after the Festival until the end of the thirty-day period of mourning. In other words, the mourning period was not entirely nullified, and since he did not take advantage of the allowance to cut his hair before the Festival, he must observe the prohibitions applying during the thirty-day period of mourning after the Festival as well.

Traduction : The William Davidson digital edition of the Koren Noé Talmud, with commentary by Rabbi Adin Even-Israel Steinsaltz.

MoedKatan 19a discusses writing tefillin and mezuzot and spinning tzitzit threads during the intermediate days of a festival.