And so I revealed to you a profound secret of the Merkava, that even the ancient generation did not know. And it was already explained in the fifth Gate that the prophets do not receive from a single root, for they have an infinite number of roots: sixty myriad in every world. As our teacher (Rabbah) of blessed memory said (commenting on the Song of Solomon), “Sixty thousand neviim were in Israel”. And Moses, may he rest in peace, contains them all and outweighs them.
Moses… ascended to the world of Emanation (Atzilut), from which he was able to see emanation clothed in Creation (B’riyah), for he refrained from looking at unclothed Emanation. And this is the secret (sod) of the verse “For man shall not see me and live” (Exodus 33:20), whereas the other neviim saw the world of emanation clothed in the lights of the world of Creation. Ezekiel, who lived after the destruction of the Temple, received prophecy from the Emanation after it was clothed in Creation, which was itself clothed entirely in Form (Yetzira). After this, the lights of Emanation and Creation were no longer revealed at all [at least in Judaism]. This is what our sages of blessed memory meant when they said that “when Haggai, Zechariah and Malachi died, prophecy departed from Israel” (Sotah 48b). Only the Holy Spirit remained.
The Holy Spirit (Ruach HaQodesh) is the transmission of the lights of Form, and other lights of lower levels. This is called in the Talmud “Ascending to Paradise”, which refers to to the world of Formation, also called the World of Metatron. There are known techniques through which one can open the Gates of the Lower World; the Material World (Asiyah) and the World of Form. Moreover, there are the proper unifications (yichudim) and prayers through which one can enter the world of Form and its Ten Spheres (Sephirot`).
These techniques are the secrets that are taught in the chapters of Ascensions (Hichalot`); techniques that were used by the rabbis Nechuniah, Akiva and Ishmael, and the members of the Great Assembly (Knesset G’dola), and then forgotten. Moreover, the ashes of the sacrificial heifer were lost in the period of the
Amoraim sages of the Talmud, during the time of Abaya and Rava, as was mentioned in Hagigah 25. Thus, since then, no one ascended to the Pardes.
From then on, they only used the technique concerning the World of Matter, for this is the lowest of the worlds, and its angels contain more evil than good. Moreover, in this world, good and evil are closely connected. Thus it is impossible to attain the Holy Spirit in it, for it is impossible to separate good from evil; and one’s attainment is therefore a mixture of good and evil, truth and falsehood.
This is the secret of Practical Qabalah (Qabalah Maasit`). It is forbidden to make use of it because whoever attempts to use it necessarily attaches himself to the evil that is attached to the good (in this world). One may actually intend to cleanse his animal spirit (nefesh), but as a result of the evil, he actually defiles it. Even if one does attain some insight, it is a mixture of truth and falsehood, especially since the ashes of the sacrificial heifer no longer exist. The impurity of the Shells (Qlipot`) attaches itself to the man who attempts to attain insight through Applied Qabalah. Therefore, he who takes utmost care should keep far from them. For besides polluting his spirit, he will be punished in Gehenna. According to our tradition, he will be punished in this world; either he or his offspring will become sick, or will become apostate.
You should learn from Joseph Della Reina and the rabbi Shlomo Molcho, who used applied qabalah and perished, and all this because there is no good here without evil, as was mentioned above. Besides, they coerce their spirits with oaths against their wills, and as a result they are enticed and drawn into evil ways, until their spirits are lost. In addition, these methods and oaths were concealed by earlier generations, and we do not know their methods well enough (to use them safely and effectively).
Therefore, it is better to keep far from these things.
–Chaim Vital, “Gates of Holiness”