beside the cushion Irrelevant, beside the point; wrong. This obsolete expression dating from the 1500s is synonymous with beside the mark. Both expressions are thought to derive from archery. An idea or comment which misses the point or is “beside the cushion” is like an arrow which misses the target (cushion) entirely.

beside the mark Irrelevant, not to the point, inapplicable; off base, off target. This expression is thought to derive from the unsuccessful attempt of an archer to hit the “mark” or target. Beside the mark appeared in print by the 1600s. Miss the mark, a verbal expression meaning ‘to be irrelevant or far-fetched,’ appeared in a slightly different form as early as the 14th century.