अस्यापीयमहङ्कारादिकारणत्वात्कारणशरीरमानन्द
प्रचुरत्वात्कोशवदाच्छादकत्वाच्चानन्दमयकोशः
सर्वोपरमत्वात्सुषुप्तिरत एव स्थूलसूक्ष्मशरीरप्रपञ्च
लयस्थानमिति च उच्यते
In plain words
For Prājña too this is called the Kāraṇa-śarīra because it is the cause of Ahaṅkāra and the rest; the Ānandamaya-kośa because it abounds in bliss and conceals like a sheath; and Suṣupti because everything ceases there. It is therefore the place where gross and subtle body-manifestation dissolves.