An Idea about the Unperishable – Mundaka Upanishad (Chapter2 Canto2 Verse5)

यस्मिन्द्यौः पृथिवी चान्तरिक्षमोतं मनः सह प्राणैश्च सर्वैः ।
तमेवैकं जानथ आत्मानमन्या वाचो विमुञ्चथामृतस्यैष सेतुः ॥ ५ ॥

jasmindyauh pruthibi chantarakhyamotam mana sah praanesch sarbaih
tame baikam jaanatha aatmaanamnyaa baacho bimunchathasas mrutasyesa setuh

(Mundaka Upanishad Chapter2 Canto2 Verse5)

Know that SELF alone that is one without a second on which are strung heaven, the Earth and the interspace, the mind and the vital Energies, together with, all the other organs and give up all other talks. This is the bridge leading to Immortality.