The best of them is as a brier: the most upright is sharper than a thorn hedge: the day of thy watchmen and thy visitation cometh; now shall be their perplexity. The best of them is as a brier - They are useless in themselves, and cannot be touched without wounding him that comes in contact with them. He alludes to the thick thorn hedges, still frequent in Palestine.
The day of thy watchmen - The day of vengeance, which the prophets have foreseen and proclaimed, is at hand. Now shall be their perplexity; no more wrapping up, all shall be unfolded. In that day every man will wish that he were different from what he is found to be; but he shall be judged for what he is, and for the deeds he has done.