Normally, we conclude the Amida prayer by reciting, "Ose Shalom Bi’mromav Hu Ya’ase Shalom Alenu..." In this brief prayer, which is based upon a verse in the Book of Iyob (25:2), we ask God to make peace among people here on earth just as He makes peace in the heavens. Our Sages teach that some angels are made from fire, and others from water. Although fire normally extinguishes water, God ensures that all the heavenly angels exist together in perfect peace and harmony. We therefore pray that here on earth, too, despite the vastly different natures and temperaments of different people, God should see to it that we all live together peacefully without conflicts.
The Sha’ar Ha’kavanot writes that during the Aseret Yemeh Teshuba, the Ten Days of Repentance from Rosh Hashanah through Yom Kippur, we slightly modify the text of this prayer, adding the letter "Heh" and reciting, "Ose Ha’shalom Bi’mromav" ("He who makes THE peace in His high places"). The reason, as the Arizal (Rav Yishak Luria, 1534-1572) explained, is that the word "Ha’shalom" has the same numerical value as "Safriel," the name of the angel assigned the task of inscribing in the Book of Life the names of those who are judged meritoriously. We allude to his name in our prayers during the Yamim Nora’im as an expression of our hope to be included in the Book of Life. The Arizal said that one should have this intention while reciting "Ose Ha’shalom."
This change to "Ose Ha’shalom" is not made every time we recite "Ose Shalom Bim’romav." We change to "Ose Ha’shalom" only at the end of the Amida, or when the Hazan recites "Ose Shalom" at the end of the "Kaddish Titkabal" following the repetition of the Amida. At Shaharit and Minha, the "Kaddish Titkabal" recited by the Hazan essentially marks the conclusion of his repetition of the Amida, and he therefore recites "Ose Ha’shalom" when concluding the Kaddish in those situations. When concluding the "Kaddish Titkabal" at Arbit, however, when there is no repetition of the Amida, the Hazan does not recite "Ose Ha’shalom." Likewise, this change is not made when concluding "Ose Shalom" after a "Kaddish Yeheh Shelama Rabba," or when reciting "Ose Shalom" in Birkat Ha’mazon.
Summary: During the Aseret Yemeh Teshuba, we change the phrase "Ose Shalom Bi’mromav" to "Ose Ha’shalom Bi’mromav" at the end of the Amida prayer, and the Hazan makes this change in the "Kaddish Titkabal" during Shaharit and Minha. When reciting "Ose Ha’shalom," one should have in mind that the word "Ha’shalom" has the same numerical value as "Safriel," the name of the angel assigned the task of inscribing in the Book of Life the names of those who are judged meritoriously.
