ॐ निशि न इति चेत्, न, सम्बन्धस्य यावद्देहभावित्वाद्, दर्शयति च ॐ ॥ ४.२.१९॥
If it be argued that the soul departing at night can have no progress along the rays, then it is not so, since the connection between the nerve and the rays continues as long as the body lasts; and this is revealed in the Upanishad.