Yoga Sutras of Patanjali translated by Yogi Kalinath - Chapter 3, Verse 15
Pada 3, Sutra 15
Kramaanyatvam parinaamaanyatve hetuh
The differentiation in the sequence of these changes is the reason for the differences in the stages of transformation.
The substratum / substance changes form over time. Nothing remains the same as phenomena is characteristic of the three modes of material nature, the Gunas in action. All phenomena within the Universe whether at the molecular or cosmic level undergo sequential change. This is the overarching concept of the Trimurthi, the Hindu Trinity of Brahma, Vishnu and Maheswara respectively associated with the creative, preserving and dissolving principles. In reality nothing is ever created nor destroyed, simply transformed. Therefore, ultimately loss or differentiation of any kind is an illusion.
What can appear as chaos on the surface is really a re-ordering at a deeper level. A sequential series of occurrences that are an integral part of transformation. This is applicable for both external and internal phenomena including consciousness itself.
In the beginning the Seer becoming aware of the apparent chaos through the agitation and perturbation of the mind, applies restraint in order to access deeper levels of awareness until awareness of awareness itself is experienced, the I AM devoid of any object.