The Pulpit Commentary on James 3:3

Illustration of the last statement of James 3:2. The bit in the horse's mouth enables us to turn about the whole body. So the man who can govern his tongue has the mastery over the whole body. A remarkable parallel is afforded by Sophocles, 'Antigone,' 1.

470, σμικρῷ χαλινῷ δ οἷδα τοὺς θυμουμένους ἵππους καταρτυθέιτας. So also Philo, 'De Op. Mundi,' p. 19, τὸ θυμικώτατον ζῶον ἵππος ῥᾳδίως ἄγεται χαλινωθείς. The manuscript; authority is overwhelming in favor of εἰ δὲ (A, B, K, L א, εἰδε γάρ, etc.

; and Vulgate, si autem) instead of ἰδού of the Received Text (C has ἴδε, and the Syriac ecce): thus the apodosis is contained in the words, καὶ ὅλον κ. τ. λ. Translate, with R.V., now if we put the horses' bridles into their mouths that they may obey us, we turn about their whole body also.