According to Chapter 19, how does the relationship between the Soul and the body contribute to the cycle of worldly existence?

Chapter 19 explains that the union of the Soul (Atma) and the body is an extraordinary and unavoidable exception to the rule that friendship exists only between those of similar nature. The text highlights their fundamental differences: the body is perishable, while the Soul is changeless and imperishable. Despite this, their affection for each other is so immense that one cannot bear to be without the other. It is precisely this profound love and inseparable bond between the transient body and the eternal Soul that perpetuates the cycle of worldly existence, or Samsara, as described in this chapter.