Verse 17
Iron sharpeneth iron - As hard iron, viz., steel, will bring a knife to a better edge when it is properly whetted against it: so one friend may be the means of exciting another to reflect, dive deeply into, and illustrate a subject, without which whetting or excitement, this had never taken place. Had Horace seen this proverb in the Septuagint translation when he wrote to the Pisos?
Ergo fungar vice cotis, acutum
Reddere quae ferrum valet, exors ipsa secandi.
Hor. Ars. Poet., ver. 304. "But let me sharpen others, as the hone
Gives edge to razors, though itself have none."
Francis.