Isaiah 17:6

Yet gleaning-grapes ... - They shall not all be removed, or destroyed. A “few” shall be left, as a man who is gathering grapes or olives will leave a few that are inaccessible on the topmost boughs, or the furthest branches. Those would be usually the poorest, and so it may be implied that those left in Israel would be among the poorer inhabitants of the land.

Two or three - A very few - such as would be left in gathering grapes, or in endeavoring to shake olives from a tree.

Four or five - A very few that would remain on the furthest branches, and that could not be shaken off or reached.