Leviticus 23
6 On the fifteenth day of that month the LORD’s Festival of Unleavened Bread begins; for seven days you must eat bread made without yeast.
7 On the first day hold a sacred assembly and do no regular work.
8 For seven days present a food offering to the LORD. And on the seventh day hold a sacred assembly and do no regular work.’”
Numbers 28
17 On the fifteenth day of this month there is to be a festival; for seven days eat bread made without yeast.
18 On the first day hold a sacred assembly and do no regular work.
19 Present to the Lord a food offering consisting of a burnt offering of two young bulls, one ram and seven male lambs a year old, all without defect.
20 With each bull offer a grain offering of three-tenths of an ephah of the finest flour mixed with oil; with the ram, two-tenths; 21 and with each of the seven lambs, one-tenth.
22 Include one male goat as a sin offering to make atonement for you.
23 Offer these in addition to the regular morning burnt offering.
24 In this way present the food offering every day for seven days as an aroma pleasing to the Lord; it is to be offered in addition to the regular burnt offering and its drink offering.
25 On the seventh day hold a sacred assembly and do no regular work.
Numbers 33
3 On the fifteenth day of the first month, on the day after the Passover, the Israelites set out from [the city of] Rameses. They marched out defiantly in full view of all the Egyptians, 4 who were burying all their firstborn, whom YHWH had struck down among them; for YHWH had executed judgment against their gods. 5 The Israelites set out from Rameses and camped at Succoth.
Deuteronomy 16
1 Observe the month of Aviv and celebrate the Passover of the Lord your God, because in the month of Aviv he brought you out of Egypt by night.
2 Sacrifice as the Passover to the Lord your God an animal from your flock or herd at the place the Lord will choose as a dwelling for his Name.
3 Do not eat it with bread made with yeast, but for seven days eat unleavened bread, the bread of affliction, because you left Egypt in haste—so that all the days of your life you may remember the time of your departure from Egypt.
4 Let no yeast be found in your possession in all your land for seven days. Do not let any of the meat you sacrifice on the evening of the first day remain until morning.
Deuteronomy 16
7 (…) Then in the morning return to your tents.
8 For six days eat unleavened bread and on the seventh day hold an assembly to the Lord your God and do no work.
Exodus 12
1 The Lord said to Moses and Aaron in Egypt,
2 “This month is to be for you the first month, the first month of your year.
3 Tell the whole community of Israel that on the tenth day of this month each man is to take a lamb for his family, one for each household.
4 If any household is too small for a whole lamb, they must share one with their nearest neighbor, having taken into account the number of people there are. You are to determine the amount of lamb needed in accordance with what each person will eat.
5 The animals you choose must be year-old males without defect, and you may take them from the sheep or the goats.
6 Take care of them until the fourteenth day of the month, when all the members of the community of Israel must slaughter them at twilight.
7 Then they are to take some of the blood and put it on the sides and tops of the doorframes of the houses where they eat the lambs.
8 That same night they are to eat the meat roasted over the fire, along with bitter herbs, and bread made without yeast.
9 Do not eat the meat raw or boiled in water, but roast it over a fire—with the head, legs and internal organs.
10 Do not leave any of it till morning; if some is left till morning, you must burn it.
11 This is how you are to eat it: with your cloak tucked into your belt, your sandals on your feet and your staff in your hand. Eat it in haste; it is the Lord’s Passover.
12 “On that same night I will pass through Egypt and strike down every firstborn of both people and animals, and I will bring judgment on all the gods of Egypt. I am the Lord.
13 The blood will be a sign for you on the houses where you are, and when I see the blood, I will pass over you. No destructive plague will touch you when I strike Egypt.
14 “This is a day you are to commemorate; for the generations to come you shall celebrate it as a festival to theLord—a lasting ordinance.
15 For seven days you are to eat bread made without yeast. On the first day remove the yeast from your houses, for whoever eats anything with yeast in it from the first day through the seventh must be cut off from Israel.
16 On the first day hold a sacred assembly, and another one on the seventh day. Do no work at all on these days, except to prepare food for everyone to eat; that is all you may do.
17 “Celebrate the Festival of Unleavened Bread, because it was on this very day that I brought your divisions out of Egypt. Celebrate this day as a lasting ordinance for the generations to come.
18 In the first month you are to eat bread made without yeast, from the evening of the fourteenth day until the evening of the twenty-first day.
19 For seven days no yeast is to be found in your houses. And anyone, whether foreigner or native-born, who eats anything with yeast in it must be cut off from the community of Israel.
20 Eat nothing made with yeast. Wherever you live, you must eat unleavened (bread).”
The Temple Scroll (11QT=11Q19-21, 4Q365a, 4Q524)
On the fifteenth day of this month (there shall be) a ho[ly] gathering. You shall do no work of labour on it. (It shall be) a seven-day feast of unleavened for YHWH. You shall offer on each of the[se] seven days a holocaust to YHWH: two young bulls, a ram, and seven ram lambs without blemish and a he-goat for a sin-offering and the corresponding grain-offering and drink-offering [according to the sta]tute for the young bulls, rams, l[am]bs and the he-goat. On the seventh day [(there shall be) an assembly] for [YHWH]. You shall do no work on it. XVIII … [he-] goat for a sin-offering … [the corresponding grain-offering and drink-] offering according to the statute; one tenth of fine flour [mixed with a quarter of a hin of oil and] a quarter of a hin of wine for a drink-offering … [he shall expiate] for all the guilt of the people of the assembly … This shall be an eternal [ru]le for you [for your generations wherever you dwell.]
Calendrical Document C (4Q326)
In the first (month) on the fourth (day) is Sabbath…
On the eighth (day) in it [is Sabbath] …
On the eleventh (day) in it is Sabbath…
[On the 14th (day) in it is Passover on the third (day of the week).
On the 15th (day) in it: the feast of the Unleavened Bread on the fourth (day of the week).
1 Corinthians 5:8
Therefore let us keep the feast, not with old leaven, nor with the leaven of malice and wickedness, but with the unleavened bread of sincerity and truth.
The old leaven: a symbol of sin in one's life
Luke 12:1
In the meantime, when so many thousands of the people had gathered together that they were trampling one another, he began to say to his disciples first, “Beware of the leaven of the Pharisees, which is hypocrisy.
Matthew 16:6-12
Jesus said to them, “Watch and beware of the leaven of the Pharisees and Sadducees.” And they began discussing it among themselves, saying, “We brought no bread.” But Jesus, aware of this, said, “O you of little faith, why are you discussing among yourselves the fact that you have no bread? Do you not yet perceive? Do you not remember the five loaves for the five thousand, and how many baskets you gathered? Or the seven loaves for the four thousand, and how many baskets you gathered? ...
Mark 8:15
And he cautioned them, saying, “Watch out; beware of the leaven of the Pharisees and the leaven of Herod.”
1 Corinthians 5:6-8
Your boasting is not good. Do you not know that a little leaven leavens the whole lump? Cleanse out the old leaven that you may be a new lump, as you really are unleavened. For Christ, our Passover lamb, has been sacrificed. Let us therefore celebrate the festival, not with the old leaven, the leaven of malice and evil, but with the unleavened bread of sincerity and truth.
Galatians 5:9
A little leaven leavens the whole lump.
Exodus 23:18
“You shall not offer the blood of my sacrifice with anything leavened, or let the fat of my feast remain until the morning.
Leviticus 2:11
“No grain offering that you bring to the Lord shall be made with leaven, for you shall burn no leaven nor any honey as a food offering to the Lord.