The Torah, “Exodus, (Tetzaveh),” 29:37: For seven days you shall perform atonement upon the altar and sanctify it; henceforth, the altar shall be a holy of holies. Whatever touches the altar shall be holy.
An altar refers to the general desire upon which a person raises parts of his egoistic desire that were meant to be corrected. There are parts that have to be killed because they cannot be corrected in their live state. There are parts that have to be used as food and there are parts that have to be burnt.
There are many options of correcting the desire, but they all refer to one thing only: We need to establish an intention of bestowal on top of each desire and only then use it either in the form of food or as material to burn. When burning something, the unpleasant scent that may rise symbolizes the change of the corporeal part into a spiritual one, that is, the ascent of the uncorrected desire and transforming it into the next state in the form of incense.
From KabTV’s “Secrets of the Eternal Book” 8/28/13