Yet they had a file - The Hebrew פצירה petsirah, from פצר patsar, to rub hard, is translated very differently by the versions and by critics. Our translation may be as likely as any: they permitted them the use of files, (I believe the word means grindstone), to restore the blunted edges of their tridents, axes, and goads.

Yet they had a file for the mattocks, and for the coulters, and for the forks, and for the axes,.... Those that would not go to the Philistines, or were not able, or thought it too much trouble, these kept files by them to sharpen those several instruments with upon occasion; though the words are by some rendered in connection with the preceding, to this sense, that they went to the Philistines to sharpen them, when the mouths, or edges, of the mattocks, coulters, &c. were dull; or "blunt" (i); and so needed sharpening; and even
to sharpen the goads; with which they pricked and pushed on the oxen in ploughing, when sluggish and remiss. (The word for "file" in the verse is "pim", and occurs only here in the Hebrew scriptures. It is not used elsewhere in other Hebrew writings. Therefore the translators of the 1611 Authorised Version had only the root derivation to deduce what the word meant. Literally, it means "a file with mouths". However, recently archaeologists have found a stone inscribed with this word. Also they found a stone inscribed with the word "shekel". Hence they deduced that the word was really a weight of measure equal to about one third of a shekel. Newer translations usually translate this as "the charge was a third of a shekel", hence removing the obvious contradiction between this verse and the preceding one. Editor.)
(i) "retusae itaque erant acies vomerum", V. L. "quandoquidem acies cultrorum aratri", &c. "obtusae erant", Tigurine version.

Yet they had a file--as a kind of privilege, for the purpose of sharpening sundry smaller utensils of husbandry.