Mahāprajñāpāramitā Sūtra

...is the purity of that which is produced by the mind. Why? Because the purity of that which is produced by the mind and the purity of the ear, nose, tongue, body, and mind senses are non-dual, without two divisions, undifferentiated, and unbroken. Subhuti, the purity of that which is produced by the mind is the purity of the form-sense. The purity of the form-sense is the purity of that which is produced by the mind. Why? Because the purity of that which is produced by the mind and the purity of the form-sense are non-dual, without two divisions, undifferentiated, and unbroken. The purity of that which is produced by the mind is the purity of the sound, smell, taste, touch, and dharma-senses. The purity of the sound, smell, taste, touch, and dharma-senses is the purity of that which is produced by the mind. Why? Because the purity of that which is produced by the mind and the purity of the sound, smell, taste, touch, and dharma-senses are non-dual, without two divisions, undifferentiated, and unbroken. Subhuti, the purity of that which is produced by the mind is the purity of the eye-element. The purity of the eye-element is the purity of that which is produced by the mind. Why? Because the purity of that which is produced by the mind and the purity of the eye-element are non-dual, without two divisions, undifferentiated, and unbroken. The purity of that which is produced by the mind is the purity of the form-element, the eye-consciousness element, and eye-contact, as well as all sensations born from the condition of eye-contact. The form-element up to those sensations born from the condition of eye-contact...