Eknath Easwaran's Commentary
There are two basic tools for mastering the thinking process. The first is meditation, which is described in the yoga texts with a beautifully precise image: there should be a smooth, unbroken flow of attention on a single subject, like the flow of oil poured from one vessel to another. My method of meditation is to make the mind go slowly through the words of a particular passage from the scriptures or great mystics, as slowly as possible. Whenever the mind wants to slip off on another line of thought, bring the attention back to the words of the passage. It may take practice, but eventually thought flows smoothly without interruption.
The other tool is the mantram, or mantra, which is a name or phrase with spiritual meaning and power. Meditation on an inspirational passage for half an hour every morning slows down the thinking process. Then during the day, the mantram keeps the mind from speeding up again. The mantram keeps the stream of concentrated thought flowing throughout the day.