The character of language is the appearance of the character of the mind or the attributes of the mind, which fundamentally is the clear light, the cognition devoid of inherent existence. What in tantric terms is called the self-appearance of the cloud-like wheel of letters…[is] the appearance of one’s own cognition as understood language or written language.
What this means is when you are reading written letters, you are actually reflecting back to yourself, or in your own experience, the attributes of your own mind, which are brought to mind by the language or by the understood language or the letters. So therefore, the nature or character of language is no different than the nature or character of the mind itself.
In the text, Jamgon Lodro Thaye next quotes from the Guyagarba sutra. He says: “The nature of the mind is letters. Letters have no other nature or substantial existence.”
Letters are shapes that we use through learning to understand certain meanings. The understanding of meanings is fundamentally an attribute of the mind. Aside from the physical presence of letters on a page or a screen, your actual apprehension of meaning in them is fundamentally an attribute of your mind. So therefore, the letters have no existence. The meaning that we perceive, even the letters, has no existence outside of our agreed upon understanding or conventional agreed upon attribution of meaning to them.
[From a teaching on Essence of Wisdom: Stages of the Path, Part 2, by Lama Tashi Topgyal. Translated by Lama Yeshe Gyamtso.]