Communicating a divine message to an audience that refuses to listen requires a shift in approach. A prophet facing a spiritually degraded nation finds himself forced to adapt his words to their level, highlighting a tragic disconnect between God and the people. The repetitive nature of the prophet's message illustrates the immense difficulty of breaking through to them, as well as the defiant response he receives in return.
The primary approach among commentators is that the nation is compared to small children who are simply unable to grasp complex ideas. The prophet must teach them exactly as a father instructs a young child learning to write, or as a builder slowly constructs a wall. He delivers the message commandment by commandment, line by line, and step by step. Because the people lack both the desire and the understanding to absorb the truth, he can only offer them a small amount of guidance at any given time or place. Yet, despite this painstaking and gradual effort, they still refuse to accept the teachings [אבן עזרא, רד״ק, מלבי״ם, צאינה וראינה].
Viewed from a slightly different angle, the people's constant pursuit of physical pleasures has distanced them so far from God that the prophet is forced to build boundary upon boundary and safeguard upon safeguard around the commandments of the Torah [מצודת דוד]. The people, however, perceive this careful guidance as an unbearable burden. In their eyes, the Torah is nothing more than an annoying collection of petty commands, endless restrictions, and trivial details that are beneath the dignity of mature, intelligent adults [ביאור שטיינזלץ].
Offering a different perspective, other interpretations suggest that the repetitive nature of the prophet's words reflects deep spiritual fragmentation rather than a gradual teaching method. The people perform the commandments in a purely technical manner, lacking any true intention or wholehearted devotion. Each commandment remains isolated and disconnected from the rest of their lives. They constantly waver, leaning slightly toward the Torah and slightly toward their own wicked desires, completely devoid of an authentic connection to God [שד״ל].
A completely alternative approach understands this interaction not as a teaching method at all, but as a defiant and mocking dialogue initiated by the people. When the prophet delivers a command from God, the people respond with contempt, claiming they have a more important command from their idols. When he demands true justice, they arrogantly boast about the strict boundaries of their own corrupt laws. Finally, when the prophet warns them that in just a little while disaster will strike them from God, they mockingly challenge Him to hurry up and bring the punishment without delay [רש״י, צאינה וראינה].