Read Isaiah 17:5 Using Other Translations
And it shall be as when the harvestman gathereth the corn, and reapeth the ears with his arm; and it shall be as he that gathereth ears in the valley of Rephaim.
And it shall be as when the reaper gathers standing grain and his arm harvests the ears, and as when one gleans the ears of grain in the Valley of Rephaim.
The whole land will look like a grainfield after the harvesters have gathered the grain. It will be desolate, like the fields in the valley of Rephaim after the harvest.