Iron sharpeneth iron

What is the meaning of Proverbs 27:17? How does one sharpen his friend?

Older Bible versions include the word “countenance.”

• King James Version: Iron sharpeneth iron; so a man sharpeneth the countenance of his friend.
• English Revised Version: Iron sharpeneth iron; So a man sharpeneth the countenance of his friend.
• American Standard Version: Iron sharpeneth iron; So a man sharpeneth the countenance of his friend.

Modern versions tend to be more economical with the language, and most have excluded the word “countenance.”

• New American Standard Bible: Iron sharpens iron, So one man sharpens another.
• New English Translation: As iron sharpens iron, so a person sharpens his friend.
• New International Version: As iron sharpens iron, so one person sharpens another.

Going older, Wycliffe: Iron is whetted by iron; and a man whetteth the face of his friend.

Going “literal,” Young’s Literal Translation: Iron by iron is sharpened, And a man sharpens the face of his friend.

Most people I know interpret this verse in some kind of positive sense, that the outcome is good, such as:

• The help of one friend improves the other.
• Learned men sharpen one another’s minds.
• Constructive criticism sharpens character.

Sometimes the interpretation is presented negatively, such as:

• One man’s passion incites another’s rage.

As far as I remember, I had not encountered the negative presentation. However, while recently studying and researching Proverbs 27:17, I found some old commentaries that do so. John Gill writes, “…Aben Ezra, takes it in an ill sense, that as iron strikes iron and sharpens it, so a wrathful man irritates and provokes wrath in another.” The Geneva Bible of 1599 has a note stating, “One hasty man provokes another to anger.”

Ron Giese in the Journal of Biblical Literature (Spring 2016) presents “iron sharpens iron” as a negative image, “a man causes his neighbor to go on the attack (i.e., have a ‘sharp face’).”

A brother on the Baptist Board gives the following thought:

“Sharpening creates friction and heat. In verse 6 we read, ‘Faithful are the wounds of a friend.’ So, the process may be painful but the reward is pleasant. Sometimes we are sharpened by our enemies, even when they mean us harm (cf. Genesis 50:20).”

Is this sharpening positive or negative? Either? Why?