Job pours out a profound curse against the day of his birth, wishing for it to be completely erased from existence and swallowed by total darkness and terror. The primary approach among commentators is that this darkness should act as a stain, polluting and dirtying the very memory of that day. Another perspective suggests a theme of kinship and redemption. In this view, darkness and the shadow of death claim the day as their own family, pulling it close and holding onto it forever, though some reject this idea as straying too far from the plain meaning [אבן עזרא, רלב״ג, מלבי״ם].
The day is entirely surrendered to the control of gloom and the shadow of death, representing the eternal darkness of the grave where light never reaches [רש״י, מצודת ציון]. This shadow is an inherent part of human existence. Just as a shadow lacks the sun's light, a person begins moving toward death from the moment of birth, much like a shadow stretching closer to the dark of night [תקוות אנוש]. Furthermore, the darkness described is not merely an absence of light but an active, heavy presence. A thick mass of clouds is called upon to settle over the day, actively smothering it in complete blackness [מלבי״ם].
The curse culminates in a wish for overwhelming fear, anxiety, and dread to strike the day, brought on by the surrounding darkness, preventing the day from enduring [מצודת ציון, אבן עזרא, רמב״ן]. Commentators offer three distinct ways to understand the source of this daytime terror. One approach suggests it refers to intense, burning heat, like a blazing oven. This could manifest as thick vapors rising from the heavy heat to block out the sun, or as a scorching temperature that burns like a deadly poison [מצודת דוד, רלב״ג, אבן עזרא, מלבי״ם].
A second approach understands this terror in terms of bitterness and plague. Instead of heat, the day is filled with infected air and severe illnesses that thrive in the daytime, or it reflects the dread of bitter people who curse their own existence [רמב״ן, תקוות אנוש]. A third, unique perspective points to harmful spiritual forces. In this view, the terror is caused by demons or evil entities that emerge daily to rule over the afternoon hours, casting their dread and completely destroying any power the day might hold [רש״י, שטיינזלץ, אלשיך].