Verses with the word sharpen in the Old Testament (2 verses):

1 Samuel 13:20
But all the Israelites went down to the Philistines, to sharpen every man his share, and his coulter, and his axe, and his mattock.

1 Samuel 13:21
Yet they had a file for the mattocks, and for the coulters, and for the forks, and for the axes, and to sharpen the goads.