שמות, פרק ט׳, פסוק ה׳

The looming threat of pestilence arrives with a precise divine ultimatum. Rather than striking without warning, God establishes a clear deadline for the destruction to begin [אבן עזרא, ביאור שטיינזלץ], a timeline formally delivered to the Egyptian court by Moses [קאסוטו]. This deliberate pause serves a crucial purpose, as it prevents the Egyptians from dismissing the sudden death of their livestock as a random stroke of bad luck or a natural, nationwide disease [רשב״ם, ביאור יש״ר].

Unlike other plagues that take time to develop, pestilence strikes instantly and completely. Because divine speech is equivalent to divine action, God intentionally delays the decree to give Pharaoh and his people a brief window of opportunity to repent before disaster hits [מלבי״ם]. Beyond these spiritual motives, the waiting period carries practical implications. By explicitly announcing the exact time of the plague, Moses and Aaron give the Egyptians a chance to protect their animals by bringing them inside from the fields [אור החיים]. Alternatively, this delay creates an entirely different outcome. Panicked by the impending doom, the Egyptians rush to sell their livestock to the Israelites at drastically reduced prices. This economic shift explains how the Israelites eventually leave Egypt with such vast herds [העמק דבר].

Setting the plague for the very next day shows that Moses, anticipating Pharaoh's ongoing stubbornness, refuses to negotiate and instead presents the impending disaster as an unavoidable fact [ביאור שטיינזלץ]. Waiting until the following day might also serve as an extension of the plague's duration. Since each previous plague lasted seven days, adding one more day continues a pattern from earlier plagues where extra time was requested, showing that God honors those requests by adding another day to the timeline [שפתי כהן].

The impending plague is announced by speaking of God in the third person rather than the first person. This framing indicates that God sets the schedule specifically so Moses can relay the information to the Israelites. From a mystical perspective, this phrasing hints that God and His heavenly court are acting together to execute the judgment [רבנו בחיי].

Ultimately, there is a profound irony in the establishment of this specific deadline. Moses originally demands that Pharaoh release the Israelites to celebrate a festival and offer sacrifices to God. When Pharaoh refuses, God creates His own appointed time. During this divine appointment, the sacred animals of Egypt, which the Egyptians worship as idols, are the ones sacrificed and destroyed. From this moment forward, the objects of Egyptian worship are systematically struck down [בכור שור].