The idiom "绳之以法" is formed through classical Chinese grammatical structure and semantic compounding: "绳" (shéng) originally means "rope" but here functions as a verb meaning "to restrain or punish"; "之" (zhī) is an object pronoun meaning "him/her/them"; "以" (yǐ) is a preposition meaning "with" or "according to"; and "法" (fǎ) means "the law." Thus, the phrase literally parses as "restrain them with the law," constructing a vivid metaphor of using the law as a binding rope to apprehend and punish wrongdoers, and has solidified into a fixed expression meaning "to bring someone to justice."