Balancing one line of a verse against another. It is distinctive of Hebrew poetry. when the second line repeats the thought of the first, the parallelism is called synonymous (Psalms 50:4). When it opposes the first thought, it is called antithetical (Psalms 1:6). When it expands the first thought, it is said to be synthetic parallelism (Psalms 7:2). If the expansion continues through several lines step by step, it is referred to as climactic or stairlike.