Bhagavad Gita Chapter 8, Verse 11

सर्वद्वाराणि संयम्य मनो हृदि निरुध्य च | मूर्ध्न्याधायात्मन: प्राणमास्थितो योगधारणाम् ||

sarva-dvārāṇi saṁyamya mano hṛdi nirudhya ca mūrdhny ādhāyātmanaḥ prāṇam āsthito yoga-dhāraṇām

Restraining all the gates of the body, confining the mind within the heart, fixing the life force in the head, established in yogic concentration.

Krishna describes the yogic practice: 'Sarva-dvarani samyamya'—restraining (samyamya) all (sarva) the gates (dvarani) of the body. This means closing all the sense doors—eyes, ears, nose, mouth, skin. 'Mano hridi nirudhya cha'—confining (nirudhya) the mind (manah) within (hridi) the heart (cha). The mind is withdrawn from external objects and focused within. 'Murdhny adhayatmanah pranam'—fixing (adhaya) the life force (pranam) of the self (atmanah) in the head (murdhni). 'Asthito yoga-dharanam'—established (asthitah) in yogic concentration (yoga-dharanam). This is the complete practice: close all sense doors, withdraw the mind to the heart, fix the life force in the head, and establish yogic concentration. This is the practice for remembering Krishna at death—complete withdrawal and concentration.