Who (Τις). Rhetorical interrogative like Luke 11:11. Common in Paul and characteristic of the diatribe. James here returns to the standpoint of verse James 3:1 about many teachers. Speech and wisdom are both liable to abuse (1. Corinthians 1:5; 1. Corinthians 1:17; 1. Corinthians 2:1-3).

Wise and understanding (σοφος κα επιστημων). Σοφος is used for the practical teacher (verse James 3:1), επιστημων (old word from επισταμα, here only in N.T.) for an expert, a skilled and scientific person with a tone of superiority. In Deuteronomy 1:13; Deuteronomy 1:15; Deuteronomy 4:6, the two terms are practically synonyms.

Let him shew (δειξατω). First aorist active imperative of δεικνυμ, old verb to show. As about faith in James 2:18. Emphatic position of this verb.

By his good life (εκ της καλης αναστροφης). For this literary Koine word from αναστρεφομα (walk, conduct) see Galatians 1:13. Actions speak louder than words even in the case of the professional wise man. Cf. 1. Peter 1:15.

In meekness of wisdom (εν πραυτητ σοφιας). As in James 1:21 of the listener, so here of the teacher. Cf. Matthew 5:5; Matthew 11:29 and Zac 9:9 of King Messiah quoted in Matthew 21:5. Startling combination.