“The yogis who practice such breathing exercises are very soon freed from all mental disturbances, just as gold, when put into fire and fanned with air, becomes free from all impurities.


“This process of purifying the mind is also recommended by Lord Caitanya; He says that one should chant Hare Krsna. He says further, param vijayate: “All glories to Sri Krsna sankirtana!” All glories are given to the chanting of the holy names of Krsna because as soon as one begins this process of chanting, the mind becomes purified. Ceto-darpana-marjanam: [Cc. Antya 20.12] by chanting the holy name of Krsna one is cleansed of the dirt that accumulates in the mind. One can purify the mind either by the breathing process or by the chanting process, just as one can purify gold by putting it in a fire and fanning it with a bellows.”

Srimad Bhagavatam 3.28.10

“God is a consuming Fire. He alone can refine us like gold, and separate us from
the slag and dross of our selfish individualities to fuse us into this wholeness
of perfect unity that will reflect His own Triune Life forever…

“As long as we do not permit His love to consume us entirely and to unite us in Himself,
the gold that is in us will be hidden by the rock and dirt which keep us separate
from one another.”

Thomas Merton. New Seeds of Contemplation. (New York: New Directions Books 1961)
p 70.