Adam, the first vegetarian?
ויאמר אלקים הנה נתתי לכם את-כל-עשב זרע זרע אשר על-פני כל-הארץ ואת-כל-העץ אשר-בו פרי-עץ זרע זרע לכם יהיה לאכלה: ולכל-חית הארץ וגו’
G-d said: “Behold, I have given to you every seed-bearing plant on the face of the earth, and every tree that has seed-bearing fruit. They shall be yours for consumption, and for all the animals of the land…”
Our Sages make an interesting inference from the way Hashem gave permission to Adam and the animals to consume the plant-life that surrounded them. He said that the plants shall be for you and the animals to consume, with the inference being that, in contrast, the animals shall not be for you to consume. Meaning, only plant-life was permitted, but not animals. This seemingly would make Adam the first vegetarian. It was only during the times of Noach, after the flood, that meat became permissible for humans to consume. The gemarra asks on this from a different teaching. We are informed that while Adam was in Gan Eden, the Angels would roast meat and strain wine for him. The primordial snake saw this and grew jealous, and the rest is history. From this accounting, he seemingly did consume meat. What’s the resolution?
Before addressing the gemarra’s own answer, Rashi’s comment on the above verse might indicate how he reconciled these two teachings. When Rashi paraphrases the Sages teaching regarding the prohibition on meat, he says that Adam and his wife were forbidden from killing animals. This ostensibly implies that if an animal were to die on its own, it would have been permissible for consumption. Indeed, there are those who understand Rashi to be saying this is what the Sage’s meant all along. However, others disagree, and hold that in no way was there permission for him to eat meat. All Rashi meant to convey was the reason for the general prohibition on meat. At this point in history Hashem didn’t want mankind killing all the animals for their personal consumption, so He forbade them entirely until Noach.
When the gemarra brought the two teachings, that Adam was forbidden from consuming meat, and that the Angels roasted meat for him, what was its own resolution? According to the first understanding of Rashi, the gemarra should have answered that the Angels roasted meat from animals which had died on their own. However, that is not what it says. The gemarra innovates that the Angels were roasting for him meat which “fell from heaven”. The gemarra goes on to discuss whether such a phenomenon even exists. Apparently, such meat isn’t really considered meat, so it doesn’t fall under the blanket prohibition against its consumption. According to those who say that all meat was prohibited to Adam, it makes sense why the gemarra had to come on to such an unusual answer. However, according to those who say that animals which died on their own were permissible, why didn’t the gemarra just give this simpler answer?
Some make a keen observation of the presentation of the gemarra. It first says that the Angels roasted meat for Adam. Then it seems to say something extraneous. It relates that the snake saw the Angels honoring Adam, and he got jealous. Why did they add this detail? Perhaps it was to address this very question. According to those who permit it, the obvious answer to how the Angels roasted meat for Adam was that it was from animals which died on their own. That was never the question. The Sages mention the snake to point out when this Angelic barbeque occurred. This was before Adam’s sin. Before Adam’s sin, death didn’t exist in the world. Once Adam ate from the Tree of Knowledge, he became mortal. Our Sages tell us that not only did he and his wife eat from it, but all the animals ate from it. All creatures from that time onward became mortal.
If the Angels were roasting meat for Adam before the sin, the meat couldn’t have been from an animal which died on its own. No animal died! According to all opinions then, the gemarra had no choice but to suggest that the meat that they were roasting was meat which fell from heaven. It turns out then that while in Gan Eden, all would agree that Adam was the first vegetarian.
 Based on various sources which I found and collected
 Genesis 1:29,30
 Sanhedrin 59b
 See Nefesh HaChaim 2:6 haghah § 3, which provides a deeper understanding of this teaching. Perhaps according to his approach, the gemarra’s contradiction never gets started
 V. 29
 Mizrachi ad. loc.
 Tosafos to Sanhedrin 56b s.v. אכל תאכל explicitly writes that Adam was permitted to consume meat from an animal which died on its own
 Gur Aryeh ad. loc. § 73. See also his Chiddushei Aggados to Sanhedrin 59b
 This also seems to be the opinion of the Rambam in his Mishneh Torah Hilchos Melachim 9:1, with the explanation of the Kessef Mishnah ad. loc.
 Gur Aryeh loc. cit.
 Sanhedrin 59b
 See “Halachic Insights into Genetically Engineered Meat” (https://ohr.edu/5518), by my Shoel UMeishiv and Rosh Chabura at the Ohr Lagolah Halacha Kollel, Rav Yehuda Spitz, for a potential application of this phenomenon to genetically engineered meat, if to deem it as kosher, or even parve
 Chanukas HaTorah Hashmatos § 223, by Rav Avraham Yehoshua Heschel (17th century Rav of Cracow)
 Bereishis Rabbah 19:5, brought by Rashi to Genesis 3:6
 The Midrash lists domesticated and non domesticated animals, and birds. Rashi left out birds, and the commentaries explain (see Sifsei Chachamim ad. loc.) it was because there’s one bird which didn’t eat the fruit, so it remained immortal (see Rashi to Job 29:18, who seems to be describing a phoenix). If Rashi specifically listed animals to exclude birds, seemingly it was to also exclude fish. The Midrash also doesn’t mention fish. If so, that means fish didn’t eat from the Tree of Knowledge. Why then are fish mortal? I had this question for many years, until I was directed to a few sources. For one, Rav Yechiel Michel Stern, Rav of Ezras Torah, in his Otzar HaYediyos 6:22, explicitly addresses this. See there for two possible resolutions. See also Pirkei D’Rabbi Eliezer Chapter 10, which says that fish were always destined to be fed to the Leviathan. Perhaps this shows that they were never meant to be immortal
 Although, this lasted only seven hours, since he first stood up in the fifth hour of the day, and was expelled from Gan Eden in the twelfth hour (Sanhedrin 38b)