On whom should be peace; used after the name of a dead person.
köken: Abbreviation of עָלָיו הַשָּׁלוֹם (with a masculine singular subject), עָלֶיהָ הַשָּׁלוֹם (with a feminine singular subject), עֲלֵיהֶם הַשָּׁלוֹם (with a masculine plural subject), or עֲלֵיהֶן הַשָּׁלוֹם (with a feminine plural subject). Hence literally “peace be upon him/her/them”.