What does Chapter 37 say causes the endless cycle of birth and death, and what are the 'nooses of death'?

Chapter 37 explains that the perpetual cycle of worldly existence (Samsara), where rebirth follows death, is caused by having a knowledge of difference. A person who believes "Parabrahman is different from me; I am not that" is always subject to this cycle. The text also explicitly identifies what it calls the 'nooses of death'. These are listed as adharma (unrighteousness), ignorance, anger, and hatred. The chapter suggests that one must cross these entirely to enter the true heavenly world, which is a state of being free from such limitations.