No meat-offering which ye shall bring to Jehovah shall be made with leaven (Lev. 2:11). Again:

Thou shalt not sacrifice the blood of My sacrifice with what is leavened (Exod. 23:18; 24:25). [2] And it was therefore also commanded, that on the seven days of the Passover they should not eat any other than unfermented or unleavened bread, as stated in Moses:

Seven days shall ye eat unleavened [bread] even on the first day ye shall cause leaven to cease from your houses; for whosoever eateth what is leavened, from the first day until the seventh day, that soul shall be cut off from Israel. In the first month, on the fourteenth day of the month, at even, ye shall eat unleavened [bread], until the one and twentieth day of the month at even seven days shall no leaven be found in your houses; for whosoever eateth what is leavened, that soul also shall be cut off from the congregation of Israel, whether he be a sojourner or born in the land (Exod. 12:15, 18-20; and elsewhere, as Exod. 13:6, 7; 23:15; 34:18; Deut. 16:3, 4). Hence the Passover is called the "Feast of Unleavened Bread" (Lev. 23:6; Num. 28:16, 17; Matt. 26:17; Luke 22:1, 7). [3] That the Passover represented the Lord's glorification, and thereby the conjunction of the Divine with the human race, will of the Lord's Divine mercy be shown elsewhere; and as the Lord's conjunction with the human race is effected through love and charity and the faith thence derived, these celestial and spiritual things were represented by the unleavened bread that they were to eat on the day of the Passover; and lest these things should be contaminated by anything profane, that which was leavened was so severely interdicted that whoever should eat of it was to be cutoff; for whoever profanes celestial and spiritual things cannot fail to perish. Everyone can see that apart from this secret meaning, this ceremonial, to which there was attached so severe a penalty, would never have been given. [4] Everything that was commanded in that church represented some secret thing, even the very cooking, as was the case with every particular of what the sons of Israel did when they went forth from Egypt; to wit:

They shall eat on that night flesh roasted with fire, and unleavened bread upon bitter herbs they shall not eat it raw, nor boiled in water; the head shall be on the legs they shall not leave of it until the morning, but shall burn the residue with fire (Exod. 12:8-10). These particulars, namely, that they should eat it by night, the flesh roasted with fire, the unleavened bread upon bitter herbs, the head on the legs, not raw, nor boiled in water, that they should not leave of it until the morning, and that they should burn the residue with fire, were representative. But the arcana represented cannot possibly appear unless disclosed by the internal sense; it is from this sense alone that it can be seen that all things are Divine. [5] In like manner with the ritual in regard to the Nazirite:

The priest shall take the boiled shoulder of a ram, and one unleavened cake out of a basket, and one unleavened wafer, and shall put them upon the palms of the Nazirite, after he has shaved his nazariteship (Num. 6:19). He who does not know that the Nazirite represented the celestial man himself, does not know that celestial things, thus arcana which do not appear in the letter, are enfolded within all these particulars, namely, the boiled shoulder of a ram, the unleavened cake, the unleavened wafer, and the shaving of the hair; which shows what kind of an opinion concerning the Word must be formed by those who do not believe that it contains an internal sense; for without what is internal these are particulars of no moment: whereas when the ceremonial or ritual is removed, everything there becomes Divine and holy. The same is the case with everything else, as here with the unleavened bread, which denotes the holy of love, or a holy of holies, as it is likewise called in Moses:

The unleavened bread that is left shall be eaten by Aaron and his sons in a place of holiness, for it is a holy of holies (Lev. 6:16, 17). The "unleavened bread" therefore denotes pure love; and the "baking of what is unleavened" denotes purification.