Having explained the forms in which the Sefirot appear, we will now explain how even this vision is not a vision of a physical form.
The proposition has two parts: Part 1: Although the Sefirot... The forms in which the Sefirot appear are not like physical forms. Part 2: Even the spiritual form that is seen... Even this subtle form is not intrinsic to the Sefirot but was purposely chosen.
Part 1: Although the Sefirot appear as forms and likenesses, even so, the form that appears is not like a physical form. Thus Moses said to the Children of Israel, “For you did not see any form” (Deuteronomy 4:15). For it is certainly impossible that the Supreme Glory could appear even symbolically in any physical form or likeness whatever. For even the soul has no physical form whatever, let alone the Supreme Glory. It is therefore not possible that the physical form of a lion or an ox or a man or a circle or a straight line would appear in the upper realm. Thus it is written: “But you saw no form, only a voice” (ibid. 4:12). The vision we are talking about is the vision of the soul, which means understanding rather than vision in the physical sense. The soul does not see what it sees as external physical forms. Rather, the prophet’s soul gains insight into the true spiritual essence of what he “sees”, after which his intellect forms a mental picture or image of it. If one could see into the prophet’s soul, one would see that subtle mental or spiritual picture there.