Q. My question for you, is about Passover. If Jesus fulfilled the law, why did He do passover the day before, on Preparation day. Is it because He was the Passover Lamb? (thus fulfilling the law!)
A. The 14th of the Jewish Month Nisan is Passover. Many Jews eat a small ceremonial meal on that day. On the 15th they all celebrate the Feast of Unleavened Bread with a huge leisurely meal. Over the years this meal has become known as the Passover Meal, and the 14th was called Preparation Day, because that’s the day they prepare the meal. (The 15th is a Sabbath and no work is permitted.)
Jewish days begin at sunset, so just after sunset Jesus ate the Passover, then was arrested, tried, convicted, crucified, and buried, all on the 14th, Passover. In doing so, He fulfilled all the Passover Prophecies concerning the Lamb of God.