"In Sinu Abraham" is a Latin phrase that means "in the bosom of Abraham." It refers to the biblical story of Lazarus, who was carried by angels to the bosom of Abraham after he died. As the phrase has a unique meaning, it's hard to find synonyms that could convey the same message. However, one could use terms that describe a state of comfort or protection, such as "in the shelter of," "in the embrace of," or "in the safety of." Alternatively, one could use more secular terms, such as "in a state of serenity," "in a peaceful place," or "in a tranquil setting".