The “good side” is called “support.” He has what to count on, meaning he has a foundation.
The “side of the harsh judgment” means that he has no foundation on which to build the structure of the kingdom of heaven. At that time, he is in a state of “hangs the earth on nothing.”
The “middle line” is the Creator, meaning that He helps.
“Grateful for the past” is the “right line,” and “that which You are destined to do with me” means the “left line,” which is also in the future, which is what he still does not have, which is called “a lack.” And yet, he is thankful and praises as though he has already received a filling for his lack and does not stay separated during his criticism.
“Desiring mercy” means he is not looking at himself, at what he has, but looks at the Creator, at what the Creator has. The Creator has wholeness; therefore, he is serving the Whole One.
The Kli [vessel] in which to feel spirituality is generally called Neshama [soul], and the Neshama comprises five qualities called NRNHY.