The Chinese idiom 一如既往 (yī rú jì wǎng) is formed through a classical grammatical structure where two bisyllabic units combine to create a figurative meaning. The first part, 一如 (yī rú), meaning "exactly like" or "wholly as", originates from Buddhist scripture, denoting complete identity. The second part, 既往 (jì wǎng), is a classical phrase meaning "what has already passed" or "the past". When combined, the literal construction "wholly as the past" functions as a metaphor to express the abstract idea of unwavering continuity, meaning "just as before" or "as always". Its formation exemplifies how fixed four-character idioms (chéngyǔ) often crystallize from historical literary language into a modern expression describing consistent behavior or unchanged circumstances.