The phrase "son of peace" here is a metaphor for a person who wants peace with God and with people. Alternate translation: "a peaceful person" (See: [[rc://en/ta/man/jit/figs-metaphor]])
Here "peace" is described as a living thing that can choose where to stay. Alternate translation: "he will have the peace you blessed him with" (See: [[rc://en/ta/man/jit/figs-personification]])
It may be helpful to restate the entire phrase. Alternate translation: "if there is no person of peace there" or "if the owner of the house is not a peaceful person" (See: [[rc://en/ta/man/jit/figs-ellipsis]])
Here "peace" is described as a living thing that can choose to leave. Alternate translation: "you will have that peace" or "he will not receive the peace you blessed him with" (See: [[rc://en/ta/man/jit/figs-personification]])