People often pour vast amounts of effort and resources into pursuits that fail to provide lasting fulfillment. Using the language of economics and physical hunger, the prophecy creates a sharp contrast between wasting energy on temporary things and finding eternal spiritual nourishment through God and His Torah.
The primary approach among commentators views this misdirected effort as a critique of spending time and money on foreign wisdom and human philosophy. These subjects offer no true benefit to the body or the soul, leaving a person trapped in endless doubts without any genuine satisfaction, which stands in stark contrast to the absolute certainty of prophecy [אבן עזרא, רד״ק, מצודת דוד, צאינה וראינה, אברבנאל]. Alternatively, this useless spending represents the endless chase after material desires and wealth. Physical food digests quickly and fails to bring lasting happiness, meaning the money spent on it is ultimately lost without providing eternal satisfaction [שד״ל, אדרת אליהו, אהבת יהונתן, ביאור שטיינזלץ]. Other perspectives view this as a rebuke against paying forced taxes in submission to foreign kings and enemies [רש״י, שד״ל], or paying false prophets who sell empty nonsense, especially when the prophets of God teach the truth entirely for free [מלבי״ם].
As an answer to this emptiness, there is an invitation to listen to God, which means accepting the Torah. The Torah is considered the ultimate good and is directly compared to bread [מצודת דוד, רד״ק, צאינה וראינה, מלבי״ם]. This comparison is highly intentional. Just as bread relies on rain falling from the sky to grow and serves as the absolute foundation of physical life, the Torah was given by God from heaven and serves as the foundation for the soul's existence. Furthermore, just as bread is eaten alongside other foods to enhance them, the Torah is the foundational lens through which all other forms of wisdom can be properly understood and elevated. Consuming this spiritual nourishment also refers to the practical action of performing the Commandments [אברבנאל].
The ultimate promise is a profound pampering and richness for the soul [מצודת ציון]. Just as rich, heavy foods bring deep pleasure to the physical body, the study of Torah and the absorption of pure beliefs bring immense spiritual pleasure to the soul [רד״ק, אברבנאל, מלבי״ם]. This delight is not limited to our current existence. Rather, it is primarily a promise of the eternal reward and spiritual life that the soul will experience in the World to Come, long after the physical body has passed away [אבן עזרא, רד״ק, מצודת דוד, אברבנאל, אדרת אליהו].