What are the benefits of fasting from food? Or is it always to be understood as a sexual matter?
When reading Matt. Ch. 4, kabbalistically it is apparent that Master Ieshuah was practicing a sexual fast. Since he had just been baptized (practiced sexual alchemy), then went into the wilderness. Which could be understood as being left alone, like with no consort, and refrained from eating (or transmuting), in order to be challenged by his desire. Paul also mentioned a couple only denying one another sexually under mutual agreement and only temporarily so as not to be overcome by desire. So after the 40 (Mem - mayim - lower waters) days, Master Ieshuah was hungering. Or the original Greek word used their could indicate desire or craving. Then the devil (his animal nature) said if you are the son of God, turn the stone to bread, or in other words transmute the sexual energy. But Master Ieshuah said, man cannot live on the transmuted sexual energy alone, but by every word that proceeds from the mouth (Peh) of IAO. Then it reads as though the devil leads him into higher and higher states of desire to tempt him, which he of course overcomes totally and thus eliminates the egos of sexual craving. At this point the angels come and minister (serve) him. As in he gained control over the forces of nature. This is the way that it reads to me.
So that being said:
A. Why fast from food at all?
B. Why was Master Ieshuah abstaining from transmuting and at what point in one's Initiation is this necessary?
In my personal experience, when one practices alchemy regularly. If one discontinues for whatever reason, a new type of desire can manifest. Not for the pleasure of the orgasm, but for the "bread" rather. So it makes sense that at some point one would need to break themselves of that vice as well.