Brihadaranyaka Upanishad 4.31

तद्यथा रथमाहितमुपद्रष्टुमसक्तो भवति एवमेवायं शरीरं प्रतिपश्यन्नसक्तो भवति स यदायं पुरुषो यथा प्रायमुपन्यसत्ये ध्मायिष्णुः अत्यन्तानन्दी च सन्नथास्यैव शरीरस्य प्रत्यक्षस्य अन्तमैति ॥

tad yathaa ratham aahitam upadrashtum asakto bhavati evam evaayam shariiram pratipashyann asakto bhavati sa yadaayam purusho yathaa praayam upanyasatye dhmaayishhnuh atyantaanandii cha sann athasyaiva shariirasya pratyakshasya antam aiti

Just as one on a chariot looks at the two wheels from a detached position, even so does the Self look at the body without attachment. When this person, the one who is about to die, becomes feeble and as if unconscious, then these vital breaths gather around him.

जैसे रथ-आसीन व्यक्ति दोनों चक्रों को विरक्त-भाव से देखता है, वैसे ही यह आत्मा शरीर को असक्त-भाव से देखता है। जब यह पुरुष म्रियमाण होकर मानो श्वास खींचता-छोड़ता हुआ, मानो अति-आनन्दित-सा होता है, तब इस प्रत्यक्ष शरीर का अन्त निकट आ जाता है।