This looks like AI-buddhism, a "fork" of buddhism rewritten by an uber-LLM of the future, in which it will discard everything it cannot relate to. To such an AI, the only internal process is a sequence of words, and nothing is thinkable outside such a sequence.

However, we can imagine images, shapes and sounds, indescribable in words, and even higher there are abstract ideas that can't be expressed with images or sounds, let along with words.

The "thoughts from without" may appear for a multitude of reasons, because our minds aren't isolated systems. The source may be some sensory input that triggered a memory, and I wouldn't even reject the possibility, that brains can react to background electromagnetic noise and form thoughts based on it.