Historic memory, and the perspective and wisdom it provides, is absolutely critical to Jewish religious life and morality.

This fundamental value is given dramatic ritual expression through the observance of Yizkor, the memorial service recited four times each year. At Yizkor, we mourn our personal losses and bereavements, but we also look beyond our own pain. In many congregations, Yizkor prayers are offered for the martyrs of Jewish history, for the victims of the Holocaust, and for fallen soldiers of the Israel Defense Force. In my own congregation’s Yizkor observances, we list names of IDF casualties and we post names of Israeli victims of terror.

Yizkor is most widely associated with Yom Kippur, perhaps simply because of the unrivalled number of Jews participating in High Holy Day worship, perhaps because the martyrology service recited on the same day reinforces both the mourning and the historic speculation inherent in Yizkor, and perhaps because (at least in the popular imagination) only Yom Kippur embodies sufficient holiness to merit the sacred process of preserving memory.

It is, however, the festival of Shavuot for which Yizkor originally was introduced to Jewish worship. Memorial prayers were offered by European communities in response to the murders and massacres that had been perpetrated in the wake of the First Crusade, in the period just before Shavuot 1096. In time, the Shavuot memorial grew to become an integral element of all the major festival seasons.

Yizkor on Shavuot is a particularly charged spiritual enterprise, not merely because of the origins of Yizkor on that festival, but because Shavuot celebrates the spiritual foundation of the Jewish nation — the revelation of the Torah at Sinai and its continuing interpretation throughout the ages. At Yizkor on Shavuot, we must honestly and carefully examine the extent to which our own lives and actions are worthy of the historic legacy we have been bequeathed. Yizkor on Shavuot thus is a time of moral peril: Will we see beyond our own pain and learn from our history? Will we have the spiritual fortitude and moral clarity to summon a worthy religious response to the pain of others?

In response to this challenge, this Shavuot my congregation will include in our Yizkor observances prayers for the 21 Egyptian Christians, adherents of the Coptic Orthodox Church, who were beheaded by ISIS in Libya, many of them declaring their fealty to the Christian savior with their final breaths. The murders were recorded in a ghastly video shown by some news outlets and disseminated on the internet. Other murders and acts of persecution against Christians have followed, establishing a sustained pattern of genocidal intent.

Yizkor was created in response to religious persecution and religiously motivated violence. From nine centuries of Yizkor, we must learn the moral imperative to feel — and far more importantly, adequately to express — outrage when such heinous acts are perpetrated. Jews properly celebrate those “Righteous Among the Nations” who spoke out and took decisive action when Jewish lives were threatened and Jews routinely were murdered. They heroically met the defining moral challenge of their times.

This Shavuot forces the question: Will we see beyond our own pain and learn from our history? Will we have the spiritual fortitude and moral clarity to summon a worthy religious response to the pain of others? Will there be Righteous among OUR nation, prepared to speak out and to take decisive action when others are persecuted and murdered?

The Coptic Church, among the oldest in Christendom — tracing its founding back 1900 years to Saint Mark the Apostle — has canonized these 21 ISIS victims, placing them on the church’s official roll of martyrs, and setting a date for their liturgical commemoration: the eighth day of the month of Amshar. Significantly, that month on the church calendar roughly coincides with the Hebrew month of Adar, in which we celebrate Purim, commemorating the thwarting of murderous designs against the Jewish people. Purim imposes its own moral mandates on us.

On Shavuot, we celebrate God’s gift of the Torah, the Torah in which we are commanded to “Love your neighbor as yourself” (Leviticus 19:18). On Shavuot, we celebrate God’s gift of the Torah, the Torah in which we are commanded, “Do not despise the Egyptian” — despite our harsh national experience in Egypt (Deuteronomy 23:8). On Shavuot, we celebrate God’s gift of the Torah — the Torah in which we are commanded “Do not stand idly by the blood of your neighbor” (Leviticus 19:16). On Shavuot we celebrate God’s gift of the Torah — the Torah in which we are commanded, in reference to those who have persecuted and murdered us, “Remember… Do not forget!” (Deuteronomy 25:17, 19). On this particular Shavuot, we simultaneously embody these imperatives and we celebrate God’s gift of the Torah by — as a matter of Jewish principle — memorializing the 21 sons of our daughter faith, murdered by the ocean’s edge by ISIS, for that faith:

“Yizkor Elohim… May God remember the souls of Milad Makeen Zaky, Abanub Ayad Atiya, Maged Solaiman Shehata, Yusuf Shukry Yunan, Kirollos Shokry Fawzy, Bishoy Astafanus Kamel, Somaily Astafanus Kamel, Malak Ibrahim Sinweet, Tawadros Yusuf Tawadros, Girgis Milad Sinweet, Mina Fayez Aziz, Hany Abdelmesih Salib, Bishoy Adel Khalaf, Samuel Alham Wilson, Ezat Bishri Naseef, Loqa Nagaty, Gaber Munir Adly, Esam Badir Samir, Malak Fraq Abram, Sameh Salah Faruq, and the last of the 21, an unknown laborer from the village of Awr.

“May their lives be bound up in the bond of life eternal, and may the memory of their suffering and faith inspire us to lives of moral clarity and courage. May God fulfill the prophecy of Isaiah: ‘They shall not hurt nor destroy in all My holy mountain, for the earth shall be full of the knowledge of the Lord, as the waters cover the sea.’ And let us say: Amen.”