Atonement for sin requires that the moral flaw which activated the misdeed be purged. One who speaks disparagingly of others is arrogant. A person who puts others down is haughty. The metzora must now humble himself as contrition for his sin.
Rashi explains that the three items which the metzora brought allude to the metzora’s resolve to humble himself: Cedarwood which grows tall, imposing and wide, symbolizes arrogance. The wool thread which is dyed with a pigment made from a lowly creature and the hyssop, which is a lowly bush, represents the penitent’s newly found humility. He who used to raise himself high as a cedar will now resolve to lower himself to the level of a hyssop.
The Chidushei Ha’Rim suggests that this idea can similarly apply in the converse. He who has humbled himself as a hyssop should now raise himself high as a cedar. There are certainly occasions when one reacts by displaying a sense of misplaced humility. For instance, an individual may be asked to participate in assisting someone, helping in a community project, or taking a stand on an issue. He responds that he is not on the proper “level” to participate with everyone else; he is not great enough. This attitude is nothing more than a refusal to accept responsibility. Indeed, if this individual has not received his due respect, he is quick to assert that his honor has been slighted. When one’s priorities are confused, even the most virtuous behavior can be transformed into a dishonorable deed.