To counteract this, the practice upon a single stuff (is proposed).
artham = for
eka = single
tattva = subject
For counteracting with the obstacles and the ensuing experiences, the meditation on a single subject is to be practised.
The mind is the current of thoughts. It generates thought after thought. The perceptions are the source of thought generation. The organ of senses perceive things. The mind is attached to the sense organs. The mind is incapable of perceiving two objects at a time. If a new stuff is coming to the mind based on the current sensory perception, the mind has to leave behind the existing stuff and will engage itself with the newer one, because of its incapacity to more than one thought. This is what distraction is. To address distractions, the mind should be engaged on a single object. The meditation, Japa, prayer and the like are the means to be employed in achieving this goal.
Commentary by Maharishi Vyasha
For the prevention, let there be the practice on a single principle
For the prevention of distraction, the mind should concentrate on a single principle. The mind is perceiving many things one after another, hence normally it is not concentrated on a single principle. At any given time, the mind is limited to have a single object. It goes on changing the object. If the mind is constantly fixed on a single object continuously, distractions are prevented. It is evident that the mind stuff is one and it has many objects. If one perception of one object brings another perception of the same object which is dissimilar and heterogeneous, then the one perception is the remembrancer of another perception and one would experience the latent karma gathered in another perception. Such perception, even though it is agreed and it would surpass the falsity of the maxim the cow-dung and milk pudding.
If different perceptions are of different mind stuff, it will do away with the cognition of his own self. For example, consider the perceptions: I am touching what I am seeing and I am seeing what I am touching. Though these two perceptions are different, the perceiving agent identifies them as identical. It is not possible if these two perceptions were of two different mind stuff. The perceiving authority is not affected by any proof. Any other proof has its origin in perceptions only.
Hence the mind stuff is one which is fixed upon different objects and stable.
Commentary by Swami Vivekananda
To remedy this practice of one subject (should be made).
Making the mind take the form of one object for some time will destroy these obstacles. This is general advice. In the following aphorisms, it will be expanded and particularised. As one practice cannot suit everyone, various methods will be advanced, and everyone by actual experience will find out that which helps him most.
Commentary by Sri Osho
TO REMOVE THESE, MEDITATE ON ONE PRINCIPLE.
These symptoms of a distracted mind can be removed by meditating on one principle. That one principle is Pranava-Aum, the universal sound.