שמות, פרק י״ג, פסוק י׳

The conclusion of the Exodus narrative presents a lasting directive for future generations, demanding that the memory of leaving Egypt be actively and carefully preserved. Commentators debate the specific focus of this enduring obligation. One approach suggests the instruction centers on the laws of the Passover sacrifice [רשב״ם, ביאור יש״ר, קאסוטו]. This is supported by the mention of an appointed time, pointing to a seasonal, annual event rather than a daily practice [משכיל לדוד]. Conversely, another perspective argues that the directive connects directly to the immediately preceding topic of phylacteries [מלבי״ם]. Following this view, the command implies a duty of physical protection and extra purity. Consequently, a child is only permitted to wear phylacteries once he knows how to maintain strict bodily cleanliness [מלבי״ם, תורה תמימה]. A third approach bridges these views, asserting that the obligation applies to both Passover and phylacteries. This dual focus emphasizes that even the greatest scholars are never exempt from these physical actions and must continuously work to strengthen their faith [העמק דבר].

The fixed timing of the commandment serves as a double witness for the people of Israel, showing that God's name rests upon them [מנחת שי]. When applying this to the Passover festival, the requirement to observe the practice cyclically is understood to mean from year to year. A year is described in terms of days because a complete year gathers a full cycle of all possible days, encompassing the heat, the cold, and the shifting seasons [שד״ל, רלב״ג]. Furthermore, it hints at the complex need to calculate and balance the solar and lunar calendars [ביאור יש״ר]. This places a clear responsibility on the rabbinic court to calculate and establish the calendar and festival dates for future years [רבינו חננאל, רבנו בחיי, אבן עזרא]. On a spiritual level, returning to the Passover experience year after year ensures that the original spiritual light of the Exodus continues to illuminate our lives anew [חומש קה״ת].

Applying this cyclical timeframe to the daily practice of wearing phylacteries raises interesting considerations. Some explain it simply means observing the practice from time to time [נתינה לגר]. Others interpret the phrasing as a strict limitation, meaning the obligation applies only during the daytime and not at night; in fact, wearing them at night is considered a violation. Furthermore, it implies some days but not all days, specifically exempting Sabbaths and festivals. Since those special days serve as a sign of the covenant themselves, an additional physical sign is unnecessary [תורה תמימה, קיצור בעל הטורים, שפתי כהן]. Finally, the timeframe offers a practical instruction to inspect the parchment scrolls inside the phylacteries for defects once every twelve months. However, a dissenting opinion maintains that they never require inspection unless they have been visibly exposed to damage [רבנו בחיי, חזקוני, הדר זקנים, תורה תמימה].