1. Bhagavad-Gita As It Is Chapter 6 Text 35-36
Controlling the mind by practice and attachment.
No self realization - without controlling mind.

2. mano durnigrahaà calam
Text 35
çré-bhagavän uväca
asaàçayaà mahä-bäho
mano durnigrahaà calam
abhyäsena tu kaunteya
vairägyeëa ca gåhyate
Lord Çré Kåñëa said: O mighty-armed son of Kunté, it is undoubtedly very difficult to curb the restless mind, but it is possible by suitable practice and by detachment.

3. Controlling the mind
By practice and detachment it is possible to control the mind.
By the practice of Kåñëa consciousness.
The first and foremost of such devotional engagements is hearing about Kåñëa.
Vairägya means detachment from matter and engagement of the mind in spirit.
This is practical because by hearing about Kåñëa one becomes automatically attached to the Supreme Spirit.

4. Text 36 asaàyatätmanä yogo duñpräpa iti me matiù vaçyätmanä tu yatatä
çakyo 'väptum upäyataù
For one whose mind is unbridled, self-realization is difficult work. But he whose mind is controlled and who strives by appropriate means is assured of success. That is My opinion.

5. No self realization - without controlling mind.
One who does not accept the proper treatment to detach the mind from material engagement can hardly achieve success in self-realization.
Trying to practice yoga while engaging the mind in material enjoyment is like trying to ignite a fire while pouring water on it.
A Kåñëa conscious person easily achieves the result of yoga practice without separate endeavor