Threshing sledge

Behold, I make of you a threshing sledge, new, sharp, and having teeth; you shall thresh the mountains and crush them, and you shall make the hills like chaff; Isaiah 41:15-16 ESV
Translating unknown objects is one of the more interesting translation problems. The text above speaks of a threshing sledge, a farm implement no longer in use in most of the world. The threshing sledge is unknown to most Americans of whom only 2% are farmers and even they don’t use threshing sledges. The New Living Translation gets around the problem by using a more generic term for sledge, calling it an instrument.
You will be a new threshing instrument with many sharp teeth.
Isaiah 41:15-16
Using a more generic term is a frequently-used method for dealing with unknown objects. When the Bible mentions an unknown animal, the best translation may be “an animal called…”
English speakers have an advantage, especially in these days of Google search. You can Google threshing sledge and find out about them. Or you can consult a Bible dictionary or encyclopedia. Those who speak small languages don’t have those options. That puts more responsibility on the transistor, widening the acceptable translation options, in my opinion.
When a passage mentions an unknown item, it can be a distraction. Readers tend to focus on the unknown item, distracting them from the meaning of the text. The meaning of the passage can get lost in the details. You can research threshing sledge all you want: finding out that it was made of wood studded with pieces of flint, and that it was used to separate the edible parts of grain from the inedible. But that detail adds little, if anything, to the point of this particular passage. It’s a classic case of not seeing the forest for the trees. Here’s a translation of the passage that translates little-known and unknown terms as generically as possible in order to get to the point.

Look, I’ll make you into such a powerful, sharp-toothed new farm implement that you’ll grind up mountains and hills into flakes blown away by the wind.

In this translstion threshing sledge becomes more generic – a farm implement (which it is). Thresh become more generic too – grind up. Finally chaff become the much more genetic flakes. The details could be put in footnotes. To my mind, the loss of detail is more than compensated by this translation returning the passage to its intended focus and power.
Whether you agree with this particular use of generics for translating unknown or little-known objects, I hope I have given you a little window into the practice of translation

Man with threshing sledge 1937