Jamieson, Fausset and Brown on Isaiah 7:23

23. where there were, &c.--where up to that time there was so valuable a vineyard as to have in it a 1000 vines, worth a silverling (shekel, about 2s. 3d.; a large price) each, there shall be only briers (So 8:11). Vineyards are estimated by the number of the vines, and the goodness of the kind of vine. Judea admits of a high state of cultivation, and requires it, in order to be productive; its present barrenness is due to neglect.