John Ritenbaugh observes that someone had recently taught that Passover, rather than the Night to be Much Observed, should be designated the first day of Unleavened Bread. Leviticus 23:5-6 designates two separate festivals: the Passover (on Abib/Nisan 14) and the Feast of Unleavened Bread (on Abib/Nisan 15; see also Numbers 28:16-18). Deuteronomy 16:6 indicates that the Passover took place on the eve of Nisan 14 at ben ha arbayim (twilight). Numbers 33:3 clearly shows that the departure from Egypt took place on Nisan 15, the day after the Passover. Exodus 12:18 delineates that the eating of unleavened bread runs from the end of Nisan 14 (at ba erev - the end of the day) to the end of Nisan 21 (at ba erev). John 13:29; Matthew 26:5; John 19:31; 40-42 plainly prove that Christ, the disciples, the chief priests, the Jews, and Nicodemus did not consider the Passover a holy day, but a preparation day.
John Ritenbaugh links inextricably the time frame for the covenant with Abraham (the Selfsame Day), the events of the Passover, the Exodus, the Night to be Much Observed, and the events of Christ's Passover meal with his disciples leading to his crucifixion. Clear connections relating to the bread and wine symbols, the ratification of the covenant, and the sacrifices are convincingly drawn. The mistaken inference made by some about a wavesheaf offering in Joshua 5 ignores the prohibition against a foreigner's grain (Leviticus 22:25), a blemished offering (Leviticus 23:12) and against animal sacrifices until peace could be established (Deuteronomy 12:11). The wavesheaf offering (Leviticus 23:15) is reckoned from the weekly sabbath within the Days of Unleavened Bread and not immediately before when an annual sabbath follows immediately.
John Ritenbaugh insists that nine steps had to be included with the Passover process, including the eating of the lamb, all within the house until the morning. The time frame designated for Passover was ben ha arbayim—a period of time between the going down of the sun and complete darkness (dusk), totally within the confines of the designated day, in this case the fourteenth, as God had commanded. To use scholarship that contradicts the Bible—relying upon tradition rather than God's Word—is not unlike carrying the Ark of the Covenant in the oxcart.