The daily routine of the Tabernacle and Temple is anchored by a constant rhythm of continual sacrifices, framing the entire day from morning until afternoon. The instruction to prepare the first sheep points back to the animals previously designated for this daily service [אור החיים, ביאור יש״ר]. The selection process requires finding the finest and most exceptional sheep in the flock, as performing the Commandment beautifully brings special merits and long life [העמק דבר, פרדס יוסף]. Practically, the morning offering stands on its own. If only one sheep is available, it must be offered in the morning, even if there is no second sheep for the afternoon. The lack of the afternoon sacrifice does not prevent the morning service from taking place [אור החיים].
Though they can function independently, the two daily offerings are deeply connected and represent a complete spiritual system. The morning sacrifice symbolizes the Written Torah, which serves as the foundation, while the afternoon sacrifice represents the Oral Torah that accompanies and completes it [העמק דבר]. The atmosphere surrounding each offering also differs. The morning hours naturally carry a greater sense of joy. Because of this, the singing of the Levites during the morning sacrifice is a strict requirement from the Torah itself. In contrast, the singing during the afternoon service was established by the Sages, and its absence does not invalidate the offering [פרדס יוסף].
The designation of the afternoon sheep as the second offering carries a specific rule for the initial days of dedicating the altar. During that dedication period, the afternoon sacrifice could only be brought if the morning sacrifice had already been offered, ensuring that it was literally second. For all future generations, however, the afternoon sacrifice is required even if the morning offering was missed [רלב״ג, מלבי״ם].
The designated time for this second sacrifice is during the afternoon [ביאור שטיינזלץ]. This period officially begins at midday, when the sun tilts toward the west and begins its descent, and continues until sunset [רלב״ג, הכתב והקבלה]. Within this six-hour window, the Temple practice was to aim for the exact middle. Consequently, the afternoon slaughter was delayed until about eight and a half hours into the day. This timing served a practical purpose: it left plenty of time earlier in the day to bring individual and public sacrifices, as no other offerings were permitted after the afternoon continual sacrifice. The only exception to this schedule occurred when the eve of Passover fell on a Friday. On that day, the afternoon sacrifice was moved earlier to ensure there was enough time to comfortably slaughter and roast the many Passover offerings before the Sabbath began [הכתב והקבלה].