Aqeb means heel, footstep, or the track left by a foot. It appears about 13 times and carries extraordinary theological significance because of its connection to the name Jacob (Ya'aqob — 'he grasps the heel' or 'supplanter'). The heel is both a symbol of vulnerability and of the mechanism of supplanting/tripping an adversary.
Genesis 3:15 — the protoevangelium — uses the related verbal root: the serpent will 'strike the heel' of the woman's seed, while the seed will 'crush the head' of the serpent. This predicts a lethal but ultimately victorious wound to the Messiah. Jacob was born grasping Esau's aqeb (Genesis 25:26), foreshadowing his supplanting nature. Psalm 41:9, quoted by Jesus at the Last Supper ('he who ate my bread has lifted his heel against me' — John 13:18), connects Judas's betrayal to the ancient heel motif. The aqeb thus runs through the entire Bible as a symbol of the Messiah's vulnerable but victorious encounter with evil.