Iron, after it is converted into gold by the touch of philosopher's stone, may be kept under the ground or thrown into a rubbish heap; it will always remain gold and will not return to its former condition. Similar is the state of the man whose soul has touched, even once, the feet of the Almighty Lord. Whether he dwells in the bustle of the world, or in the solitude of the forest, nothing ever contaminates him.
As quoted in Hindu Psychology : Its Meaning for the West (1946) by Swami Akhilananda, p. 204