במדבר, פרק ל״ב, פסוק י׳

The reaction to the devastating sin in the desert broke away from standard patterns of divine justice, bringing about a uniquely severe consequence. Typically, God's anger takes one of two forms: an immediate punishment that is brief, or a gradual penalty drawn out over a long period. In this specific instance, however, both forms of judgment struck at once [מלבי״ם].

The response was instantaneous. On that very day, God grew angry and issued an immediate decree, swearing that none of the adult men would ever set foot in the Promised Land. The only exceptions to this harsh reality were Caleb and Joshua. Even Moses, at that time, was included in this sweeping judgment.

Yet, the swiftness of the decree did not mean it was short-lived. Alongside the instant punishment, God's anger stretched out over four decades of wandering in the wilderness. Because of this extended delay, the next generation also had to carry the burden of their fathers' guilt, suffering through the long years in the desert as a direct result of the original sin.