Hyssop is a member of the mint family. Its fuzzy leaves and branches produce bunches of small white or yellow flowers. During Passover, the people of Israel used hyssop branches to place blood above their doors and on their doorposts (Ex. 12:22). In Psalm 51, hyssop symbolizes being cleansed from sin (see Lev. 14:4–6; Num. 19:6).