Why does a nightmare disappear as soon as one recollects the Buddha during it?

When the mind consciousness habitually engages in recollection of the Buddha (buddhānusmṛti), the manas becomes infused with it. With the Buddha present in the manas's mind, it also understands the benefits of reciting the Buddha's name. Thus, when encountering a dangerous situation in a dream, it directly raises the thought of the Buddha and recites the Buddha's name—the name comes out spontaneously, without the mind consciousness needing to deliberate and decide to recite. Being able to recite the Buddha's name in a dream is true recollection of the Buddha, and one can thereby resonate with the Buddha. Once the Buddha's power blesses and protects, the nightmare vanishes. Circumstances turn with the mind; dream states are even more illusory than waking reality, so as soon as the mind of reciting the Buddha's name appears, the nightmare realm disappears, and the state of mind transforms from suffering into calm serenity.