Shabbat 10 - Giving a gift
Rava bar Mechasya said in the name of Rav, "One who gives a gift to his friend has to inform him." What is his source? When God gave Jews the Shabbat, He said, " To know that I am God who sanctifies them ." The words "to know" mean this: God told Moses, "I have a wonderful present in My treasure house, and its name is Shabbat, go and tell them."
In the same vein, Rabban Shimon ben Gamliel taught that if one gives bread or other food to a child, he has to inform the child's parents. How does he do it? He rubs a little oil or rubs cosmetic paint on the child's eye - the parents will ask the child about it, and he will tell them about the present. Today, though, this may arouse suspicion, so it's better to rub some of the food that he gave.
However, Rav Chama taught that one should NOT tell about a gift, based on the phrase in the Torah, " And Moses did NOT know that the skin of his face became radiant. " How is this to be reconciled? - It's no problem really, Rav Chama meant a situation where the gift will become revealed in any case, and that is why one does not have to inform about it. Rabban Shimon ben Gamliel was talking about a situation where the gift would otherwise not be revealed, and one has to tell about it, to increased the amount of good feelings and friendship among people.
However, Shabbat is known - it is a good day of rest, so why did God ask Moses to inform about it? - While it is true that the day itself is known for its rest, the reward for it in the future world is not known, and that is why God had to tell about it.
Art: Gabriel Metsu - The Hunter's Gift