Beitzah 16 - Fixed income

A person's available income for the year is fixed and is decided on Rosh Hashanah. Therefore one should not make extravagant purchases - because his income for food won't be increased. However, he can freely spend more for Shabbat and Yom Tov's needs and the Torah education of his children - because the extra amounts will be added to his allotment. Shammai would always buy things in honor of Shabbat from the first day of the week, and if he saw something better - he would buy that too and eat the previous one on a weekday. On the other hand, Hillel was unconcerned, trusting that God would provide him with the needs for Shabbat when the day came.

If one gives a present to his fellow, he need not inform him, because it will become known to his fellow anyway, and the goal of increased friendship will be achieved. When giving people the Shabbat, why did God tell Moses to inform them about it - even though they were soon to experience it!? - True, but God told Moses to inform them of the hidden qualities of Shabbat: the reward that one gets for it, and the extra soul that one gets on Shabbat and that allows him to eat more with pleasure.

Back to the subject of "eruv." Eruv is food that permits one to cook on a Holiday for the needs of Shabbat.  One can use any food for that, even a remainder of a dish. Even if he eats it on a Holiday, it still has the legal effect, provided that there is a little of it left.

Art: The feast by Adriaen Brouwer