I don’t know the source of this idea, but once an idea gets started, it tends to build momentum, particularly if the seeker has no way to assess the truth of it, and even more so when a teacher who seems authoritative promotes the idea.
We often associate a quiet mind, a mind free of disturbing thoughts, as the source of peacefulness. But this is not the true source of peace. Peace comes from aligning with the Divine, from awakening to and abiding in our deeper nature, the deep living silence of our divine nature and Divine Reality.
Awakening does not require the elimination of thoughts. The profound deep silence I refer to is not disturbed by thoughts. Thoughts can co-exist in this silence, but they become transparent, penetrated by the deep silence. Thoughts cease to be a limitation to peace. They represent no problem in and of themselves.
Having thoughts is not a sign of a failure in one’s spiritual progress. When the idea that thoughtlessness is required for awakening is perpetrated, it sets up expectations and disappointments for spiritual seekers. And struggling with spiritual practice intended to eliminate thoughts, or to permanently meditate thoughts away, is likely to fail.
Sometimes awakening stills the mind to such a degree that one temporarily fails to notice thoughts are still present. It could seem thoughts have vanished. But in due course they will reappear. If a seeker believes that thoughts should have been eliminated in awakening, imagine the confusion one might feel when after awakening, thoughts return. Imagine the doubt that would arise.
The focus should be not on eliminating thoughts, but instead aligning with the Divine, preparing for Divine Grace, and increasing one’s receptivity to Divine Presence.