Bhagavad Gita 8.12

सर्वद्वाराणि संयम्य मनो हृदि निरुध्य च।मूर्ध्न्याधायात्मनः प्राणमास्थितो योगधारणाम् ॥८.१२॥

sarvadvārāṇi saṃyamya mano hṛdi nirudhya camūrdhnyādhāyātmanaḥ prāṇamāsthito yogadhāraṇām

Having closed all the gates, confined the mind in the heart, and fixed the life-breath in the head, engage in the practice of concentration.

गीता