Hyssop

Hyssop (a plant/herb) is associated with purification and cleansing from sin in the Bible. A few examples:

  • At the Passover, the Israelites used hyssop to put the blood of the sacrificial lamb on the door (shortly before the Exodus).
  • God commanded the Israelites to use hyssop in ritual sprinklings and cleansings (Leviticus 14:4-6, 49-52).
  • David used hyssop after committing adultery with Bathsheba to seek forgiveness.
  • When Jesus was on the cross,  the stalk of a hyssop plant was used to give Jesus wine vinegar because of His thirst.

More details of this can be found here or here.