Passover: Israel's annual festival remembering the night God spared its firstborn and brought the people out of Egypt, together with the lamb and meal at its heart
Passover is not a Greek word at all. It is the Aramaic and Hebrew name for the festival (pesach), carried over into Greek sound for sound, so the New Testament writers use one fixed, unchanging form for it. That single word covers a whole cluster of closely tied ideas, and context decides which is in view.
Sometimes it names the festival itself, the fixed point in the year that drew crowds up to Jerusalem. Sometimes it names the lamb that was killed for the occasion, and sometimes the meal eaten that evening. These are not separate words but three angles on one event: the feast, its sacrifice, and its supper. To "keep" or "prepare" the Passover is to observe the whole rite.
Because the festival was built on a lamb whose death rescued the people, early Christians heard in it a picture of Jesus. Paul draws the line directly, calling Christ "our Passover," the true sacrifice whose death delivers. That figurative use grows straight out of the ordinary sense of the sacrificial lamb.
Nuances
Whether πάσχα in John 18:28 denotes the paschal supper proper or the wider festival offerings (the chagigah) eaten through Passover week.
- majorityIt refers to the Passover meal itself, so John presents Jesus dying as the lambs are killed, before the supper the Synoptics report as already eaten.; BDAG, s.v. πάσχα
- minorityIt refers to the additional festival sacrifices eaten across Passover week, so John and the Synoptics can be harmonized.; J. Jeremias, The Eucharistic Words of Jesus (London: SCM, 1966)