Can you explain the relationship between the Soul and the body as detailed in Chapter 19, and why it's considered an exception?

According to Chapter 19, the union of the Soul (Atma) and the body is a supreme and unavoidable exception to the common rule that "friendship exists between those of similar nature and habits." The chapter highlights their fundamental differences: the body is perishable, while the Soul is changeless and imperishable. Despite this, their affection for each other is described as extraordinary, to the point that they cannot bear separation. It is this immense love and attachment, as explained in Chapter 19, that perpetuates the cycle of worldly existence, or Samsara.