This can be a little confusing for those who equate Jewish traditions concerning the holy days with biblical evidence.
The bible draws a difference between "Passover" and "the days of unleavened bread".
Lev 23:5 In the fourteenth day of the first month at even is the LORD's passover.
Indeed Passover, Nisan 14, is NOT a sabbath biblically speaking.
Lev 23:6 And on the fifteenth day of the same month is the feast of unleavened bread unto the LORD: seven days ye must eat unleavened bread.
Lev 23:7 In the first day ye shall have a holy convocation: ye shall do no servile work therein.
But the first day of unleavened bread IS.
Christ died on Passover, which is not a sabbath. But the first day of unleavened bread IS a high holy day.
The confusion comes about because most Jews today consider "passover" and the days of unleavened bread to be synonomous and that they begin NOT on Nisan 14, as the bible says, but Nisan 15, the first days of unleavened bread.
For example, Judaism 101 says about Passover:
"Pesach begins on the 15th day of the Jewish month of Nissan. "
Now clearly the bible says passover IS on Nissan 14. So Jewish tradition shouldn't be the benchmark of how holy days are observed.
Well, you found a good source for the fact that the Jews celebrate the Passover on the 15th, following the tradition of the Sanhedrin, but that there was biblical reason for Christ having his passover a day earlier, on the 14th.
But here’s the thing: You still haven’t shown where the bible calls the Feast of the Unleavened Bread a Sabbath. And even if it were, that would only make it more unbelievable that an event which happened on a Saturday AFTER such a Sabbath would be said to have happened “on the first of the Sabbaths.”
You may say to yourself “a holy convocation with no labor... isn’t that a Sabbath?” You’d be wrong. Sabbath comes from the Jewish word, Shabot. The word for “Seven” is Shabiyiy. The Sabbath is the seventh day. Hence, the SEVENTH day of the Feast of Unleavened Bread is a Sabbath. The first day is not. Notice the word, “shabbath” (”rest”) isn’t used to describe the lack of labor, lest the Shabbath be confused with a Shabot. (Yes, the words are related.)
Consider this language, used in Leviticus, after establishing these feast days (also including Penteocost, Rosh Hashannah, Yom Kippur, etc:)
“These the feasts of the LORD, which ye shall proclaim holy convocations [Miqra] , to offer an offering made by fire unto the LORD, a burnt offering, and a meat offering, a sacrifice, and drink offerings, every thing upon his day:
beside the sabbaths of the LORD, and beside your gifts, and beside all your vows, and beside all your freewill offerings, which ye give unto the LORD”
See, these days are called “Miqra,” and they are to be given to the Lord BESIDES the Sabbaths, gifts, vows, etc.
>> Christ died on Passover, which is not a sabbath. But the first day of unleavened bread IS a high holy day. <<
No, the lamb is slaughtered the day BEFORE Passover. The ambiguity of Leviticus (the Jews take Lev 23:5 to mean that the Passover starts at the evening of the 14th) permitted Christ to have himself sacrificed as the Paschal lamb AFTER sharing the passover meal with his disciples.