Iron sharpeneth iron; so a man sharpeneth the countenance of his friend.
Iron sharpeneth iron (Ecclesiastes 10:10 ); so a man sharpeneth the countenance of his friend - i:e., sharpeneth the mind of his friend, so that the countenance expresses it; by mutual conversation and instruction; by the communion of saints. The countenance brightens up in meeting intelligent friends, who sharpen the intellect and warm the heart (Job 4:3-4). So Jarchi. Aben-Ezra refers it to anger: 'So a man (by his passion) sharpeneth the countenance (i:e., the anger) of another' (cf. Job 16:9). I prefer the English version. 'The very sight of a good man delights' (Seneca). (Ecclesiastes 4:9-12.)