Proverbs 26:8 - Coke's Commentary on the Holy Bible

As he that bindeth a stone in a sling— The plain meaning of this seems to be, what Bishop Patrick has given in his paraphrase; "As a stone put into a sling stays not long there, so is that honour thrown away which is bestowed upon a fool." Houbigant explains it in the same manner. Some of the versions render it, As he who throweth a stone to Mercury's heap; which is supposed to be an allusion to the superstitious custom, obliging passengers to throw a stone to such heaps in honour of Mercury; but it is very doubtful whether this custom was so old as Solomon's time. See Calmet's note. Parkhurst supposes the meaning to be, As a spark, or small piece of precious stone, in a heap of stones, so is he who giveth honour to a fool. The precious stone in one case, and the honour in the other, are thrown away and lost. See his Lexicon on the word רגם ragam.