Hyssop

(Heb. 'ezob; LXX. hyssopos), first mentioned in Ex. 12:22 in
connection with the institution of the Passover. We find it
afterwards mentioned in Lev. 14:4, 6, 52; Num. 19:6, 18; Heb.
9:19. It is spoken of as a plant "springing out of the wall" (1
Kings 4:33). Many conjectures have been formed as to what this
plant really was. Some contend that it was a species of marjoram
(origanum), six species of which are found in Israel. Others
with more probability think that it was the caper plant, the
Capparis spinosa of Linnaeus. This plant grew in Egypt, in the
desert of Sinai, and in Israel. It was capable of producing a
stem three or four feet in length (Matt. 27:48; Mark 15:36.
Compare John 19:29).