SB,
From where did you gain that understanding of
Prov 27:17? It is not what Hebrew exegetes Keil & Delitzsch discover from the grammar that verse. They wrote:
This proverb expresses the influence arising from the intercourse [conversation] of man with man....
The proverb requires that the intercourse [conversation] of man with man operate in the way of sharpening the manner and forming the habits and character; that one help another to culture and polish of manner, rub off his ruggedness, round his corners, as one has to make use of iron when he sharpens iron and seeks to make it bright. The jussive form is the oratorical form of the expression of that which is done, but also of that which is to be done (
Keil & Delitzsch n.d. Commentary on the Old Testament, vol 6, pp 212-213, Bible Hub).
Allen P Ross in his commentary on
Prov 27:17 states: 'Constructive criticism between friends develops character' (Expositor's Bible Commentary, vol 5, p 1099).
The interaction, even on CFnet, of one person/mind sharpening another, is critical for Christian growth. 'One person sharpening another' is literally, 'Sharpens the face of his friend' where the face stands for the whole personality (Edgar Jones, Proverbs & Ecclesiastes, p 219)
Oz