In plain words
The Guru replied: “The destruction of mind is spoken of in two ways: destruction in its own form and formless dissolution. The former belongs to the jīvanmukta; the latter to the videhamukta. When rajas and tamas perish and mind remains only as pure sattva, that is destruction in its own form. When, at the fall of the subtle body, even that sattvic remainder subsides, that is formless dissolution.”