Pranayama

Breath-control is only an aid for mind-control(manonigraha); it will not bring about annihilation of the mind(manonasa). Like breath-control, meditation on some form
of God, repetition of mantras, diet-regulation, etc., are butaids for rendering the mind quiescent for the time-being.

Ramana Maharishi

Pranayama

In the words of Ramana Maharishi-"The source of the breath is the same as that of the mind. Therefore the subsistence of either leads to the other. The practice of stilling the mind through breath control is called yoga."