Leviticus 16:1 to 18:30, Ezekiel 22:1-19
Recall from a past week's teaching (Vayikra) that none of the standard offerings provided atonement for intentional sins. For that atonement the Israelites had to wait for Yom Kippur, whose rituals are described in this week's portion.
Why did God wait until after the death of Aharon's sons to describe the rituals of Yim Kippur?
The concept study about Iniquity described how verse 16:30 shows Yom Kippur allowing God, however briefly, to dwell within his people. This is what the Tabernacle was for! This relates to how the Tabernacle accumulates ritual impurity/uncleanness but not unholiness (16:19).
Verses 17:3-7 not only prohibit eating domesticated animals "casually" at home, they imply that anytime the meat of such an animal is to be eaten is would be a sh'lamim offering: a meal shared with God by giving him the fat, the priest the breast and right thigh, and the household the remaining meat. But in this verse God does not emphasize this fellowship—instead he emphasizes how terrible idolatry is.
Verse 16:4 says that the High Priest should enter the Holy of Holies wearing a "holy linen coat", not his usualy decorated garments. Traditional comments offer varied explanations, including that the lack of gold adornment was to show that atonement could not be bought, or that the lack of gold was because after the sin of the golden calf no new gold was allowed into the Holy of Holies. Most common is that the plain linen clothes were the same kind of clothes a corpse would be dressed in: such linen shrouds are still worn by the rabbi and cantor at a Yom Kippur service.
According to one Midrash uses Deuteronomy 16:19 ("For a bribe blinds the eyes of the wise") to teach that the goat sent into the desert was a bribe to blind Satan. But Tradition primarily teaches that this goat was pushed of a cliff to die a slow and painful death. The Ba'al ha'Turim comments that Azazel was the name of the high rock from which this goat was pushed; the only place known to have that name was a cliff beside Sinai, but perhaps there were others. (Literally the word azazel is simply a conjunction of aiz azel, "goat that departs".) See also the comments here.
Verse 16:10 says the wilderness goat "stands alive" before God, in contrast to the slaughtered goat. This is also related to the wilderness goat being pushed off a cliff: it is not free to run about, but is not immediately dead. (To me this seems a stretch; verses 20 and 21 refer to the wilderness goat as "the alive goat" and have it standing as the High Priest lays his hands on its head.)
Tradition differentiates between verses in which someone's membership in the community is "cut off" (such as Leviticus 17:4 or 18:29) and verses in which someone's soul is "cut off" (Exodus 12:15), and verses in which the phrase "cut off" is repeated twice to show both body and soul are "cut off" (Numbers 15:31).
K'li Yakar interprets verse 18:6 as a warning against yichud (being alone with a woman, risking temptation, reproach or accusation) because the Torah writes here "Ish ish..." (emphasizing one man) as opposed to the presence of two men, which could chaperone each other when with a woman. Others, however, are not as strict against yichud and instead of ephasizing "Ish ish..." emphasize "do not come close... which in verses such as 22:14 is an euphamism for physical intimacy.
Tradition says the prohibition against sacrificing children follows the prohbitions against inappropriate sexual reltaionships to suggest that if two people did have an inappropriate sexual relationship and produce a child, that child is still valued by God: it should not be considered an evil thing that should be killed or "returned" to the forces of evil.