To understand all this by way of example, we find that whoever exerts himself mentally and emotionally during the “service of the heart” which is prayer, to comprehend and contemplate HaShem’s upper and lower unity with the recitation of “Hear O Yisrael”; the “hearing” referred to here constitutes comprehending, understanding and absorbing the matter well in his brain. Still and all, he must explain it to himself and bring it close to his human intellect, so to speak.
For example, to grasp HaShem’s lower unity he must understand how it is that HaShem brings everything into being ex nihilo (from nothingness). He does this through the use of analogies, such as the example of the letters of speech as they become revealed outside of the self or like the example of the ray of sunlight as it extends outside the body of the sun, as in the verse, “His glory is upon the earth and the heavens”. Another example is the life-force of the soul as it enlivens the body. Likewise, HaShem, blessed be He, enlivens everything.
All this only comes by way of comparison within the imagination of his mind, in which he grasps how it is by comparing it to the life-force of the soul in the body or the like. As it actually is above, however, it is impossible to draw such a comparison, because HaShem, blessed be He, lives, but not in a way comparable to how the soul enlivens the body. Rather, this is merely an analogy in order to comprehend and absorb the matter.
Now if the lower unity can only be understood by way of analogy, how much more so regarding the upper unity, which is the intellectual comprehension of how HaShem emanated the ten sefirot of Atzilut from concealment to revelation. Here too, he comprehends it all through comparisons and analogies, like the analogy of the flame that is bound to the hot coal or the analogy of the ten powers of the soul that make up the will, the intellect and the emotions that branch out into revelation from their concealed inclusion in the essential self of the soul.
This is not at all the comprehension of the true essence of the lights of Atzilut and how they are so totally unified with their Emanator that it states, “He and His life-force are One etc.” Nonetheless, with his mind’s eye he can recognize the truth of it, whether in regard to the lower unity or whether in regard to the upper unity, actually as HaShem is above. In other words, actually as HaShem, blessed be He, enlivens everything, specifically not as it is comprehended and understood by way of the above mentioned comparisons and analogies (though this level of seeing also comes through the analogy of the light and life-force of the soul in the body).
This is similarly so regarding the analogy of the letters of speech. Nonetheless the matter is absorbed as it is, in an aspect of actual G-dliness, not at all like the matter of intellectually comprehending bodily life. Rather, he recognizes it as a self evident truth, in the same way that he recognizes the truth of the life of his soul in his body, and though he does not see it with physical sight at all, it is self-evident and requires no explanation. Similarly, regarding the mind’s eye into the upper unity of Atzilut, he can recognize the truth of it, as it actually is above, from the angle of the Emanator of the ten sefirot, so to speak, rather than as it appears to him by way of comparison to the powers of the soul etc.
However, this cannot be comprehended by the intellect except through the investment of the soul in the body and through one’s own essential powers, as written, “From my flesh I shall behold G-d”. (Even though this seeing and recognizing with the mind’s eye into the emanation of the ten sefirot from the Emanator, comes about by way of the powers that are included in the soul which become revealed etc., nonetheless, in reality it is like it is above, similar to the prophetic vision of the prophets. They would see in their mind’s eye in a manner similar to physical sight, as written, “And I beheld HaShem etc.” However, this was not at all through intellectual comprehension. Nonetheless, it states, “Through the prophets I am depicted. This is called, “The appearance of the likeness of the glory of HaShem” etc.)