The Self is the Heart. The Heart is self-luminous. Light arises from the Heart and reaches the brain, which is the seat of the mind. The world is seen with the mind, that is, by the reflected light of the Self. It is perceived with the aid of the mind. When the mind is illumined it is aware of the world. When it is not itself so illumined, it is not aware of the world. If the mind is turned in towards the source of light, objective knowledge ceases and Self alone shines forth as the Heart.

The moon shines by the reflected light of the sun. When the sun has set, the moon is useful for revealing objects. When the sun has risen, no one needs the moon, although the pale disc of the moon is visible in the sky.

So it is with the mind and the Heart. The mind is useful because of its reflected light. It is used for seeing objects. When it is turned inwards, the source of illumination shines forth by itself, and the mind remains dim and useless like the moon in day-time.

~ Talks with Ramana Maharshi (98)

“The pure mind is itself Brahman; it therefore follows that Brahman is not other than the mind of the sage.”

~ Talks with Ramana Maharshi (204)

And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God.

~ Romans 12, 2

It is well known and admitted that only with the help of the mind can the mind be
killed. But instead of setting about saying there is a mind, and I want to kill it, you
begin to seek the source of the mind, and you find the mind does not exist at all. The
Mind, turned outwards, results in thoughts and objects. Turned inwards, it becomes
itself the Self.

~ Sri Ramana Maharshi

On the surface of the mental lake there are waves, your normal thought forms. Below the thought forms, you have the subconscious mind, which has its own color and dirt. And, at the very bottom of the water, you have the old sediment, which you call the samskaras, or the vasanas, which you have brought from several incarnations. The Yoga practices help to still the waves of the water and make it crystal clear so that you can get a clear vision of the Self: Tada drastuh svarupe avasthanam (Yoga Sutras, 1.3). If the mental lake is made still and clean, then you can see the Self, or the Atman, because there’s nothing to color it, there’s nothing to distort the vision, and you understand what it is—it shines in its own real glory.

~ Swami Satchidānanda

Mind can know only that which is of the same nature as itself, namely, thought.

~ Paul Brunton

He then learns that in going down into the secrets
of his own mind he has descended into the secrets of all minds.

~ Emerson

It is all the mind can do – discover the unreal
as unreal. The problem is only mental. Abandon
false ideas, that is all. There is no need of true
ideas. There aren't any.

~ Nisargadatta Maharaj

The mind can have dealings only with kindred objects formed from its own
substance, that is, with thoughts, ideas. Therefore when it knows material
objects they must really be ideas.

~ Paul Brunton

Yoga is the restraint of the modifications of the mind.
Then there is abiding in the seer's own form.

~ The Yoga Sutras

Words reduce reality to something the human mind can grasp, which isn't very much.

~ Eckhart Tolle

Sell your cleverness and buy bewilderment.

~ Rumi

Acceptance of what is immediately frees you
from mind identification and thus reconnects
you with Being. Resistance is the mind.

~ Eckhart Tolle

The intuitive mind is a sacred gift
and the rational mind is a faithful servant.
We have created a society that
honours the servant
and has forgotten the gift.

~ Albert Einstein

Cleanse the dark mirror of the mind.
~ Ko Hung

While the mind is centered in the body and consciousness is centered in the mind, awareness is unattached and unshaken. It is lucid, silent, peaceful, alert and unafraid, without desire and fear. Meditate on it as your true being and try to be it in your daily life, and you shall realize it in its fullness.

Mind is interested in what happens, while awareness is interested in the mind itself. The child is after the toy, but the mother watches the child, not the toy.

~ Nisargadatta Maharaj

It is so simple that the complex structure that is
involved doesn't want to leave it alone. That is
really the problem.
- Krishnamurti

Remembering your self is virtue, forgetting your self is sin. It all boils down to the mental or psychological link between the spirit and matter. We may call the link psyche (antahkarana).
When the psyche is raw, undeveloped, quite primitive, it is subject to gross illusions. As it grows in breadth and sensitivity, it becomes a perfect link between pure matter and pure spirit and gives meaning to matter and expression to spirit.

~ Nisargadatta Maharaj