Leprosy and Hyssop

"This shall be the Torah of the one stricken with leprosy in the day of his cleansing: He shall be brought to the priest: and the priest shall go out of the camp; and the priest shall look, and, behold, if the plague of leprosy be healed in the one afflicted; then shall the priest command to take for him that is to be cleansed two birds alive and clean, and cedar wood, and scarlet, and hyssop...” (Leviticus 14: 2-4)

Visually, it is easy to contrast the cedar and the hyssop (ezov, in Hebrew). The hyssop—representing humility, since it grows close to the ground and is easily crushed underfoot--was used to cleanse the leper of his affliction, as leprosy was thought to be a punishment for the sin of pride.

Cedar and hyssop, growing together at Neot Kedumim

Exodus 12:22 also contains an interesting association with the hyssop. Why were the Israelites required to use hyssop to mark the doorposts? Certainly G-d knew which were the houses of the Egyptians and which were the houses of the Israelites! Perhaps the use of hyssop was directed towards the Israelites themselves, as a reminder to remain humble in the face of the terrible plague that was brought on the Egyptians

"Take a bunch of hyssop, dip it in blood that is in the basin, and apply some of blood that is in the basin to the lintel and the two doorposts; and none of you shall go outside the door of his house until morning." (Exodus 12:22)