1 Samuel 13:20

Revised Standard Version (RSV-CI)

but every one of the Israelites went down to the Philistines to sharpen his plowshare, his mattock, his axe, or his sickle;

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if I whet my glittering sword, and my hand takes hold on judgment, I will take vengeance on my adversaries, and will requite those who hate me.

Now there was no smith to be found throughout all the land of Israel; for the Philistines said, “Lest the Hebrews make themselves swords or spears”;

and the charge was a pim for the plowshares and for the mattocks, and a third of a shekel for sharpening the axes and for setting the goads.

And in the cities of Manasseh, Ephraim, and Simeon, and as far as Naphtali, in their ruins round about,

Iron sharpens iron, and one man sharpens another.