Bhagavad Gita 6.36

असंयतात्मना योगो दुष्प्राप इति मे मतिः।वश्यात्मना तु यतता शक्योऽवाप्तुमुपायतः॥

asaṃyatātmanā yogo duṣprāpa iti me matiḥ |vaśyātmanā tu yatatā śakyo'vāptumupāyataḥ ||

I think Yoga is hard to be attained by one with an uncontrolled self, but the self-controlled and striving one can attain it by the appropriate means.

It is not possible to attain Self-Realization unless one knows how to control oneself; however, for one who, striving by the proper means, learns such control, it is possible.

Our plain-language meaning of this verse is waiting for scholar review.