Or HaChaim on Genesis 2:5/אור החיים על בראשית ב׳:ה׳

1 וכל שיח השדה טרם יהיה בארץ. None of the plants of the fields existed as yet. This stresses again that until the Creator irrigated the earth by bringing on rain, none of the vegetation produced by earth was able to function, to grow. The verse also tells us that the living creatures on earth were G'd's creation as indicated by 2,19, that "G'd formed all the beasts of the field." Earth's contribution was to provide the golem-like body pending G'd's infusing these bodies with a breath of life. The same applied to the swarms of "living" creatures produced by the waters as well as the birds. Our sages have already stated that the birds are the result of co-operation by water and earth, i.e. swamps (Eyruvin 28). This is why the Torah described the birds as עוף השמים, birds of the heavens, in 2,19, although the directive had been issued to the waters in 1,20.

2Why did the Torah mention here that there was as yet no human being on earth who would work the land, and why is there a second report about the creation of man in the next verse, i.e. וייצר השם אלוקים את האדם? If the Torah only wanted to inform us that the raw material man is made of was the dust of the earth, it could have done so in 1,27 where man's creation by G'd is reported instead of repeating the whole story about man being created.

3I believe the answer lies in what our sages alluded to when they described אדם הראשון, original man, as the חלת העולם, earth's gift to G'd, i.e. a concept parallel to the priest's share of the dough (Eyruvin 18). Our sages therefore believed that just as the principle of donating the first of the dough to the priest in his capacity of G'd's representative on earth is a duty, creation itself is morally bound to "donate" to its Creator something similiar. We find the following passage in the tractate חלה 2,5: "If someone sets aside the quantity of חלה that he is obliged to set aside in the form of flour (instead of as part of the dough), it (this quantity of flour) is not considered sacred." In 3,1 of the same tractate we are told that until the dough (of wheat) has developed so that the meal and the water form one body, a non-priest may still eat of it on an ad hoc basis, even if חלה has not yet been set aside from it. If one eats from such dough subsequently (knowingly) one is guilty of the death penalty. The descent of rain on the vegetation of the earth is akin to the mixing (kneading) of a dough from which to make bread. This is why consumption of the proceeds of grain i.e. bread or cake, is prohibited until חלה has been set aside. It is equivalent to what the Mishnah Challah 3,1 called גלגול העיסה. Earth was unable to produce viable vegetation without G'd contributing the rain. It follows that it is prohibited to eat or otherwise enjoy any of earth's fruit until an appropriate gift to G'd has been set aside. The creation of man [from raw material made of all parts of the earth Ed.] was that gift, i.e. that חלה. Prior to man's creation the earth was טבל, untithed produce, forbidden, out of bounds to man. This is what our verse wanted to convey. Although earth produced the plants on the third day, G'd had not provided the rain at that time, not until immediately before He formed the human being. Creation of man, i.e. the חלה of the universe, enabled all the creatures to enjoy it henceforth. The Torah mentions that the entire surface of the earth was irrigated because if G'd had irrigated only parts of the earth, such an incomplete "dough" would not have freed the remainder from the requirement to contribute further amounts of חלה.

4It is important to realise that G'd took "dust from the earth" to create man, as opposed to soil from גן עדן. This point is repeated again in 3,24 when Adam is expelled from גן עדן "to till the soil he had been taken from." There was no need to give חלה from any of the trees of גן עדן seeing it was totally holy already. This is why the Torah says (2,8) "G'd had planted a garden in Eden already previously (מקדם)," i.e. prior to the creation of man. He had prepared this holy region for Adam who was holy, being the חלה of the universe.