Passage
As in water face answereth to face, so the heart of man to man.
As in water face answereth to face, so the heart of man to man.
Proverbs 27:17 Iron sharpeneth iron; so a man sharpeneth the countenance of his friend.
Proverbs 27:18 Whoso keepeth the fig tree shall eat the fruit thereof: so he that waiteth on his master shall be honoured.
Proverbs 27:19 As in water face answereth to face, so the heart of man to man.
Proverbs 27:20 Hell and destruction are never full; so the eyes of man are never satisfied.
Proverbs 27:21 As the fining pot for silver, and the furnace for gold; so is a man to his praise.
The verse centers on "water", "face", "answereth", and "heart". It is saying that the verse draws attention to "water" and "face", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 18's "Whoso keepeth the fig tree shall eat..." into verse 20's "Hell and destruction are never full so...", so "water" and "face" belong inside that flow. In Proverbs context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "water" and "face" with trust shaped by these words, not by a vague optimism outside the passage.