Relying on No Other Beside Him
This mitzvah is placed below, for a rectified "below" means that only God is beneath me, only He supports me, and ultimately, I have no one to rely upon beside Him. All natural (or seemingly supernatural) forces, represented, in general, by the "earthly," are hereby negated as objects worthy of one's trust. Continuing the imagery of the previous mitzvah, as soon as (and to the extent that) one disconnects from the "rope" of belief in God alone, he starts to "fall" into the quicksand of reliance on natural forces.
The Path of Life
Throughout the Bible, the attribute of "sincerity" (temimut) links, idiomatically, to the verb "to walk" (as in the phrase, "he who walks sincerely…") or to the noun "way" or "path" (as in the phrase, "Happy are those of the sincere [or 'complete'] path…"). One walks the path of life on earth below. In Kabbalah, "walking" is associated, in particular, with the left leg ("the left leg controls the sense of walking"), corresponding to the Divine power ofhod, the spatial parameter of below (as explained previously).
As we have seen, the first commandment entails a consciousness of "going [literally, 'walking'] from strength to strength," above, in the eternal state of the World to Come. Its complement, the second commandment, entails a consciousness of "walking from strength to strength," below, in this world. Both of them entail a sense of time together with a consciousness of the above-below coordinate of space.