What follows was addressed in a recent post on the burning on the kometz, but I have added an analysis of the Kayin-Hevel story, and present it here as a stand-alone discussion.
ונפש כי תקריב – לא נאמר נפש בכל קרבנות נדבה אלא במנחה. מי דרכו להתנדב מנחה? עני. אמר הקב”ה מעלה אני עליו כאילו הקריב נפשו.
“And a soul who offers [a mincha sacrifice to God]” (Vayikra 2:1) – It does not say “a soul” with any of the free-will sacrifices except for the mincha. Who normally donates a mincha? A poor person. God says: “I will consider it in his case as if he has offered up his very soul.”
Rashi on Vayikra 2:1
The mincha is introduced in the first parasha of Vayikra immediately after the olah sacrifices. The Torah speaks about one who chooses to bring an olah from the cattle, or from the flock, or from birds. On one level, thus, a mincha can be seen to be on the continuum with an olah and is essentially a poor-person’s olah – if you cannot afford a large animal, give a small one; if you can’t afford an animal at all, give a grain-offering. This is reflected in the Rashi quoted above, and is even more explicit in the Mishna in Menachot:
מתני’. נאמר בעולת בהמה אשה ריח ניחוח, ובעולת עוף אשה ריח ניחוח, ובמנחה אשה ריח ניחוח, לומר לך: אחד המרבה ואחד הממעיט ובלבד שיכוין לבו לשמים.
It says by the olah of cattle, “A fire-offering, a pleasing scent,” and it says by the olah of a bird, “A fire-offering, a pleasing scent,” and it says by a mincha, “A fire-offering, a pleasing scent.” This is to tell you, Whether one does a little or one does a lot, what matters is that one’s intent is directed to God.
On another level, however, a mincha is a completely different sacrifice. While an olah can vary in value – it can be a cow, it can be a sheep, it can even be a bird – but it is a life; it is the symbol of devoting one’s life, one’s self, to God. A mincha is not that. A mincha is a gift. It is not life, it is just flour and oil. It signifies food and sustenance, or the fruits of a person’s labor, but it is not intrinsically powerful. The word mincha itself means gift – whether to God or to people (cf., Breishit 33:10), and this is different than giving of one’s life, one’s self.
This may have been at the heart of the difference between the sacrifices of Kayin and Hevel. Why did God turn to Hevel’s sacrifice and not Kayin’s? The Torah does not say. It is possible that Hevel gave a more expensive sacrifice – “the first of his flock and their fat” – as opposed to Kayin’s less expensive “fruit of the land.” This would show his greater devotion to God. On the other hand, Kayin was the one who initiated giving a sacrifice, and Hevel just followed in his footsteps, “And Hevel brought, even he…” (Breishit 4:4). Kayin’s initiative should count for at least as much as Hevel’s larger gift.
The difference, rather, lies not in the size of the gift but in its symbolism. Kayin only brings a mincha, a gift to God: “And Kayin brought from the fruit of the land a mincha to God” (Breishit 4:3). The symbolic significance of a mincha is that one acknowledges that God is to thank for one’s success, and that some of one’s wealth must be given back to God. Hevel, on the other hand, brought an animal sacrifice, a sacrifice symbolizing that his life is God’s and that he is prepared to devote his life to God. This may be the very meaning of the verse, והבל הביא גם הוא, “And Hevel brought, even he…” That is, Hevel brought not a mincha, but he brought himself: “And Hevel brought even himself” as a sacrifice to God.
Because a mincha is a gift, and not life, and not the very giving of one’s self, pacing it on the altar does not suffice. What is required is that the smoke rise up – that it become a symbolic gift to God. Once it is given to God, and by rising to the Heavens, symbolizes that God has accepted it, then a significant religious act has been done.
This connects to the position of R. Shimon, according to Rav Yanai, in Menachot (26a) that unlike the placing of blood on the altar, there is no formal act of putting the kometz of the mincha on the altar. In the case of the kometz all we care about is that the kometz is burnt, and there is no inherent significance in the act of placing it on the altar. Why is this true? I think that it is exactly the difference between giving of one’s life, and giving a gift. The act of placing blood on the altar is significant because the blood is inherently powerful. It is the life-force: “For the soul (or “life-force”) of all flesh is in the blood, and I have given it to you [to be placed on the altar] to atone for your souls… for the blood through the soul (or “life-force”) will achieve atonement.” (Vayikra 17:11). The power of the blood means that once it hits the altar, once a gesture is made to direct this life-force, this symbol of our own life, to God, then the korban has been offered, it is valid, and atonement is achieved.
When one gives of oneself – when one gives ones life-force, there is power in that very gesture, the very reaching of the altar. However, when one gives a gift, a mincha, when one makes a donation of funds, the true significance comes only once that gift is received. Thus, for R. Shimon, the act of placing the kometz on the altar is not what is significant. It is when the smoke rises up and God receives it לריח ניחוח לה’.