bindeth a stone in a sling:

Heb. putteth a precious stone in a heap of stones, This probably refers, as Coverdale understands it, to the custom of throwing a stone to the heap under which a criminal was buried. So the Vulgate, Sicut qui mittit lapidem in acervum Mercurii; ita qui tribuit insipienti honorem, "As he who throws a stone to Mercury's heap, so is he who gives honour to a fool." Mercury was a heathen god of highways; and stones were erected in different parts to guide the traveller: hence those lines of Dr. Young,

"Death stands like Mercuries in every way;
And kindly points us to our journey's end."