“…And the kohen shall cause the fat to [go up in] smoke on the altar, and the breast shall belong to Aharon and his sons…” – Vayikra 7:31

וְהִקְטִיר הַכֹּהֵן אֶת הַחֵלֶב הַמִּזְבֵּחָה וְהָיָה הֶחָזֶה לְאַהֲרֹן וּלְבָנָיו – ויקרא ז, לא

After a sacrifice in the Temple is slaughtered and some of its blood sprinkled on the Altar, the kohanim burn the choice fats of the animal on the Altar, and the remaining flesh is eaten, (with the exception of certain sacrifices that are burned in there entirety.) The verse above teaches us though eating the sacrificial meat is a mitzvah in its own right, nevertheless, the meat of the sacrifice may not be eaten before the sacrificial parts of the animal have been burnt on the Altar.

The Ramban (on Vayikra 1:9) explains that the objective of the sacrifices is truly to arouse the individual to offer himself—his inner qualities and character—to G-d. The fats of the animal represent lusciousness and pleasure. Burning the fats of the sacrifice on the Altar thus symbolizes that we must consecrate our sense of pleasure and delight to G-d alone.

Now, one might assume that this refers only to pleasure we might derive from material pursuits; meaning, that we must not seek (or derive) physical enjoyment and pleasure even when meeting our basic material needs. The requirement of burning the fats on the Altar before doing the mitzvah of eating the sacrificial meat shows us, however, that even within the realm of holiness, our “fat” must be consecrated to G-d alone. This means that in order to fulfill the Mitzvos properly, and to truly grasp the Torah’s wisdom, we must not taint these holy pursuits with the personal gratification and enjoyment that we derive from these holy pursuits.

Granted, we must study Torah and fulfill the mitzvos with joy and excitement. Our joy and delight must be, however, not from the physically enjoyable aspects of the mitzvos or even the intellectual stimulation that Torah study provides, but purely from the great merit that we have to fulfill G-d’s will and to study His wisdom.

—Likutei Sichos, vol. 3, p. 950