The King of Babylon stands at the absolute peak of his power, enjoying total rest and the endless pleasures of his rule. It is the quiet moment just before a sudden, life-altering divine intervention shatters his reality. In his own account, he begins by painting a picture of his ideal, undisturbed life right before a terrifying dream changes everything.
He describes his condition on two distinct levels. First, he notes his state of complete ease and tranquility [רש״י, אבן עזרא, ביאור שטיינזלץ]. This reflects a deep, internal peace within his home and a total break from war; the entire world is subjugated to him, and he faces no enemies from within or without [מלבי״ם, יוסף אבן יחיא]. Second, he highlights his physical flourishing, describing himself as healthy, well-fed, and full of vitality [מצודת ציון, ביאור שטיינזלץ]. Within his palace, he is completely immersed in the physical pleasures of life. This immense sense of personal power and comfort has caused him to entirely forget God [יוסף אבן יחיא]. Interestingly, the specific imagery used to describe his physical vitality borrows heavily from the plant kingdom. This is not a coincidence, but a subtle hint preparing the listener for the contents of the upcoming dream, in which the king will be compared to a great tree [מצודת דוד].
Why would the king go out of his way to emphasize his perfect tranquility right before detailing a terrifying nightmare and his subsequent illness? The primary approach among commentators explains that this contrast is meant to prove that his sudden downfall is the result of direct divine providence, rather than natural or psychological causes. Human nature dictates that nightmares, despair, and dark thoughts typically haunt those who are already suffering from stress, sadness, or physical pain. A person living in absolute security, wealth, and peace usually enjoys restful sleep and pleasant dreams. Therefore, the fact that such a horrifying, mind-breaking dream strikes him suddenly out of a state of complete calm, without any prior worries or troubling thoughts, proves beyond any doubt that his experience is a direct decree from God, rather than a natural descent into madness [אלשיך, מלבי״ם].