Bhagavad Gita · 8.12

सर्वद्वाराणि संयम्य मनो हृदि निरुध्य च।मूर्ध्न्याधायात्मनः प्राणमास्थितो योगधारणाम्॥

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

Restraining all the gates of the body, confining the mind in the heart, and fixing the life breath at the top of the head, one establishes oneself in yogic concentration.

— Bhagavad Gita 8.12

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)