Excellent and very important question. This gets to the heart of the difference between intellectual understanding and direct awareness, which is a central theme in Sayadaw U Tejaniya's teachings.

The short answer is: Using commentary as an initial tool can be helpful, but if you rely on it, it becomes a subtle obstacle to the very awareness you are trying to cultivate.

Let's break this down according to his method.

The Potential Pitfalls of Mental Commentary

Sayadaw U Tejaniya consistently warns against getting caught in conceptual thinking about the experience instead of simply knowing the experience itself.

1. It Creates an Extra Layer: The pure, direct experience of anger is one thing. The thought, "Anger is arising, and it is not me, it is just nature" is a second, separate thing—a commentary about the anger. Your awareness is now focused on the commentary, not on the actual mental state.
2. It Can Become a Mantra or Auto-Pilot: If you repeatedly apply the same phrase, "not me, not mine," it can become a mechanical repetition. The mind says the words, but it doesn't genuinely see the truth of them. You feel the anger, label it "not me," but are still fully identified with it and acting from it. The concept becomes a shield rather than an insight.
3. It Keeps the Mind Busy and Conceptual: The goal of U Tejaniya's practice is a relaxed, spacious, and non-conceptual knowing. Continuous commentary keeps the thinking mind active and prevents the mind from settling into that simpler, more direct level of awareness.

What Sayadaw U Tejaniya Recommends Instead

He advocates for a move from commentary to direct, investigative awareness.

1. Use a Simple, Gentle Question to Prompt Awareness, Not to Comment.
   The purpose of his famous questions ("What is the mind doing?" "Is the mind peaceful or busy?" "Is there wanting?") is not to get a verbal answer. It's to turn the mind's light inward to directly perceive the current state.
   · Commentary looks like: "The mind is being aware of sound. The sound is nature. It is not me."
   · Investigation looks like: Asking "What is knowing the sound?" and then simply feeling the quality of the knowing mind itself—is it relaxed, is it tense, is it interested? The knowing happens not through words, but through direct perception.
2. Shift from Labeling to Feeling the Quality.
   Instead of thinking "this is anger," feel the quality of the anger. Feel the heat, the tension, the restlessness, the pressure. Instead of thinking "this is not me," notice how the anger arises without your invitation, changes intensity, and eventually fades away. This direct observation of impermanence (Anicca) and the self-less nature (Anatta) of the phenomenon is the insight itself. The understanding should be experiential, not verbal.
3. The Understanding of "Not-Self" Should be a Conclusion, Not a Premise.
   You don't start by telling yourself "this is not me." You observe the mind and body so clearly that you see for yourself that these processes are:
   · Not controllable (you didn't decide to get angry).
   · Unsatisfactory (the feeling of anger is stressful).
   · Impersonal (they follow their own nature, like a storm or a fire).
   The realization that "this is not a self, this is just nature" dawns on you as a result of clear seeing. It's a profound understanding, not a repeated thought.

Practical Guidance: How to Work with This

· Stage 1: Using a Nudge. If you are completely identified with anger, it can be helpful to briefly use a thought like, "Ah, anger," or "This is just a mind-state," to create a moment of space. Use it as a skilful means to dis-identify just enough to start observing.
· Stage 2: Dropping the Concept and Observing. Once that initial space is created, drop the words. Don't keep talking to yourself. Shift your attention fully to the direct sensory experience—the physical sensations, the energy, the overall "flavor" of the mental state. Observe it with a relaxed, interested awareness.
· Stage 3: Resting in Simple Awareness. The ultimate goal is to abide in a state where the mind naturally and wordlessly knows what is present. The awareness and the object (anger, sound, thought) are known simultaneously without a running commentary in between.

A Quote from Sayadaw that Captures the Spirit:

"The meditator's job is only to be aware. It is not to try to change things, to judge, to comment, or to try to create a peaceful state."

Commentary is a form of "trying to change" or "trying to understand conceptually." Simple awareness is just knowing.

In summary: It is okay and natural for some commentary to arise, especially when you are new to the practice. Acknowledge it, see it as another object of awareness (a thought), and gently guide your attention back to the direct, non-conceptual experience of the primary object (the difficult emotion, the bodily tension). Let the insight of "not-self" reveal itself through patient observation, rather than you asserting it through repetitive thinking.