Motzai Shabbat & Sewing
There exists a custom for women not to perform certain household chores on Motzai Shabbat, such as sewing and knitting.[1] The origin of this custom is based on the teaching that when Mashiach comes there will no longer be a need to sew clothes. As there is an increased possibility for Mashiach to arrive on a Motzai Shabbat, the custom of not sewing clothes at this time evolved accordingly. Indeed, Motzai Shabbat is a popular time for a number of rituals and prayers relating to the coming of Mashiach.
It also just might be that the custom of not sewing on Motzai Shabbat is based on the tradition that when the Jewish people left Egypt, they brought no sewing or clothes-making utensils with them.[2] The clothes they were wearing at the time of their departure from Egypt were the only clothes they had brought with them! We are told that these clothes miraculously remained fresh and clean and even grew with them as their clothing sizes changed. Indeed, included in this Divine tailoring service was an anti-perspirant for all the hot days in the desert.[3] As Shabbat is a "zecher l'yitziat mitzrayim", a remembrance of the Exodus from Egypt, it is fitting to commemorate this on Motzai Shabbat. Furthermore, refraining from sewing recalls the teaching of "kimei tzetcha m'eretz mitzrayim arenu niflaot", as in the days when you left the land of Egypt I will show you wonders, which teaches that when Mashiach comes many of the miracles which were experienced at the time of the Exodus will be repeated.
Nevertheless, many authorities argue that there is no authentic source for this custom - at least not one which is based in any classical or authoritative sources. As such, women are free to dismiss this custom should they so desire.[4] Indeed, most women today do not subscribe to this custom and perform all household chores as normal on Motzai Shabbat.
[1] Magen Avraham O.C. 299
[2] Shir Hashirim Rabba 4
[3] Ibn Ezra;Devarim 8:4
[4] Rivevot Ephraim 2:107