We must ask the following: Why was the Land of Israel deprived of the manna?

The answer to that question is as follows: In the desert, everything of a physical and materialistic nature stems from external forces. Those entities are essentially impure and grow in a land that is ruled upon by "foreign archangels". Therefore, the fruits that grow therein can not be worthy vessels to contain the spirit of holiness. This is because an impure body cannot become the vessel for the spirit of holiness. If there were to be some holiness in its fruits and food products, they would be provided for by their [evil spiritual] rulers. Yet that possibility could not exist when it came to manna. This is because the manna comes from heaven, a place where the forces of the "foreign archangels" have absolutely no grasp. The very same spirituality that was enveloped by the manna, is enclothed by the fruits of Israel…

Nonetheless, the fruits of the Land of Israel stem from holiness. Therefore the very same spirituality that was enveloped by the manna, is enclothed by the fruits of Israel. That is why no manna fell in the Land of Israel. That is also why the after-blessing for fruits of the seven species in the Land of Israel concludes, "upon her fruits", as opposed to "upon the fruits". This that indicates that the holiness of the land resides in her fruits alone and not the fruits that grow outside the Land of Israel.

My Beloved Ramaz (Rabbi Moshe Zaccuto) comments: "The understanding of this is: The entire purpose for our existence is to sift out the sparks of light that have fallen into the realms of inanimate, plant, animal, human. (This is part of the mystery of the 288 sparks that remained from the days of Adam.) Therefore, even into the Garden of Eden the manna didn't descend for Adam. Rather he was commanded, as a positive mitzva, to eat from all the fruits of the garden, as per Rabbeinu Bachaya's explanation. Yet, in the desert the sprouting of fruits is supernatural, as it is not the essential function of the desert to contain those sparks. [Yet the manna fell for the Jews in the desert] for they had shed their defilement at the giving of the Torah on Mount Sinai.

[Note: the 288 sparks… According to the Ari, this entire process of death and resurrection is hinted at in the word "merachefet". The first and last letters of this word spell "met", meaning "dead". The three remaining letters are reish, fei and chet. The numerical value of these three letters is 288. These are the 288 sparks of holiness that resided within the vessels that shattered at the beginning of creation.

The symbolic significance of the number 288 is alluded to in the word 'Ibur' whose numerical value is also 288. Ibur means "gestation" or "pregnancy," thus indicating that the broken vessels with their 288 sparks are similar to seeds that are planted in the ground. Although they may appear to be rotting, they are going through a process that is necessary in order to bring forth new life. The 288 sparks thus represent the profound concept of death and resurrection. Our task is to rectify these sparks.] There exist ten different fruits which correspond to the ten sefirot

Rav Chaim Vital has written: "There are thirty species of fruit that grow in the Land of Israel. Each species has many differing types. This can be seen from the seventy types of dates derived from the verse "And seventy date trees" (Ex. 15:27).

Behold in the realm of Beriya, there exist ten different fruits which correspond to the ten sefirot of Beriya. Since they are distant from impurity and are close to Atzilut, these fruits have neither shell nor pit. They can be eaten entirely. [The numerous strange types of fruit mentioned here are difficult to identify with modern terms. Please forgive this.] They are:

Grapes

Figs

Apples

Etrogs

Lemons

Pears

Quinces

Berries

Surabis

Carobs

There are ten fruits correlating to the ten sefirot of Yetzira. Being that they are rooted from a place which is not too close to the impurity, yet they aren't so close to Atzilut either, therefore they have an inedible pit. They are:

Olives

Dates

Cherries

Sofiafs

Prishkus

Cyruylas

Apricots

Gindas

Acranias

Juyspulas

The ten fruits that correspond to the ten sefirot of Asiya are surrounded by an inedible shell. This is so, being that it's in close proximity to the realm of impurity. The shell acts as a protective barrier, preventing the impurity from penetrating the holiness of the fruit. This is similar to the yetzer hara and the "shell" (in Hebrew, "kelipa") that surrounds the Nefesh of a person. These ten are as follows:

Pomegranates

Hazelnuts

Almonds

Chestnuts

Brazil nuts

Alonim-Albutas

Frishis

Pinionas

Pistachios

Maosis

Their names and numbers I have received, yet their exact correspondence to their particular sefirot, I haven't received, until a spirit shall descend upon us from above.

Behold the ten fruits of Beriya have had all waste removed, leaving them totally edible. Corresponding to them [in the realm of the forces of impurity] are the barren trees. They are entirely inedible, for they are like one big shell. Vegetables
…are not arrogant…

In opposition to the ten fruits of Yetzira are their own pits. This relates to the situation where the fallen spark of holiness is so great that the "shell" can not tolerate it's light in her midst. Therefore she closes in on herself and enters the middle of the light.

The ten fruits of Asiya, where the fruit is surrounded by the shell, are similar to where the "shell" has incorporated within itself a spark of holiness.

Opposite those thirty fruits are another thirty that stem from the "Left Side". They grow wildly on the trees of forests. The majority of which contain no real edible fruit. Rather they are mostly "shell", therefore the blessing recited over them is not "…Creator of the fruit of the tree" [in Hebrew, "Borei pri ha'etz", rather the blessing is "…that all comes into being via His power of speech", in Hebrew, "Shehakol nihiyeh b'dvaro", which is a more general blessing, applicable to any food]. Anyone who is meticulous in his actions should refrain from eating them, since they signify the "Left Side" - the force of evil…

The total number of edible fruits of the ground [in Hebrew, "ha'adama"] that were created is 55, as is the value of the word "ha'adama". Other than those 55 types of vegetables, nothing is worthy of consumption. Being that the vegetables are low [i.e. close to the ground], they are not arrogant and are able to grow from any type of water.