Proverbs 27:17-21

Iron sharpeneth iron; So a man sharpeneth the countenance of his friend. Whoso keepeth the fig tree shall eat the fruit thereof: So he that waiteth on his master shall be honoured. As in water face answereth to face, So the heart of man to man. Hell and destruction are never full; So the eyes of man are never satisfied. As the fining pot for silver, and the furnace for gold; So is a man to his praise.

Proverbs 27:17-21