There are many expressions commonly used to wish someone who has passed on some peace and comfort in their afterlife. Some of the most common synonyms for "may someone rest in peace" include "may their soul find peace," "may they be at peace," "may they find eternal peace," "may they rest easy," and "may they find rest in the arms of the divine." These phrases all convey the same sentiment of hoping that the departed find peace and comfort in their eternal rest, and are often used as condolences or well-wishes when someone has lost a loved one.