G-d spoke to Moshe, saying, “Speak to the Children of Israel and let them take for Me a portion.” (Shemos 25:1-2)
The concept of taking a portion of one’s property and giving it away is not a new concept in the Torah. The first obvious place that the concept of tithing appears is here:
But Malchi-tzedek, king of Shalem, brought out bread and wine; he was a priest of G-d, the Most High. He blessed him saying, “Blessed is Avram of G-d, the Most High, Maker of heaven and earth; and blessed be G-d, the Most High, Who has delivered your foes into your hand;” and he [Avraham] gave him [Malchi-Tzedek] a tenth of everything. (Bereishis 14:20)
In other words, since Malchi-Tzedek, a.k.a. Shem, the son of Noach, was a priest, Avraham automatically removed ten percent from the booty that was collected through his military victory and gave it to him. Unlike other priests of the time, Malchi-Tzedek served G-d and not angels, therefore Avraham felt obliged to support him.
The next time the concept of “ma’aser” shows up, it is here:
Then Ya’akov took a vow saying, “If G-d will be with me, will guard me on this way that I am going; will give me bread to eat and clothes to wear; and I return in peace to my father’s house, and G-d will be a God to me – then this stone which I will have set up as a pillar shall become a house of G-d, and whatever You will give me, and I will repeatedly tithe to You.” (Bereishis 28:20-22).
Understandably, Ya’akov had been concerned. After taking the blessings right out from under Eisav’s nose and being forced into exile to avoid Eisav’s revenge, the worst was yet to come. While living in Eretz Yisroel, he could count on a special Divine Providence to protect him, but after being forced into “chutz l’aretz,” he required extra merit to warrant similar success and Divine protection against the “elements.” The promise of tithes was his way of saying, “Help me succeed and survive if only to give me the chance to give back to Heaven some of what Heaven has given to me.”
A less obvious, but earlier example of tithing was by G-d Himself, at the very creation of man. Women are commanded in challah because, as it says in Bereishis Rabbah, she [Chavah] destroyed the “challah” of the world, since Adam HaRishon, who was taken as a portion of challah, sinned through her . . . (Rashi).
In other words, when G-d made Adam HaRishon, He “kneaded” him from the ground like a woman kneads dough, as it says, “G-d formed man from the dust of the ground” (Bereishis 2:7). Taking off a portion of the dough as “challah,” as a Jewish woman is supposed to do, is symbolic of when Adam was taken as a portion from the ground, and therefore a rectification of the sin as well.
Erev Shabbos is the ideal time to fulfill this mitzvah, because that was when Adam was created and sinned. Giving the challah to the kohen (today we burn it since kohanim cannot properly purify themselves to eat it) is to remind us that our path to complete rectification is that of striving for a holy lifestyle once again.
