Quotation su Ecclesiaste 12:11

Tractate Hagiga (5a) of the Babylonian Talmud elaborates about the meandering quality of this metaphor. A prod can be used to direct a plowing cow in either direction to cut a productive furrow; but if you think that the words of the sages are so flexible, remember that they are also like nails. However, if you think that the words are merely fixed like nails, which diminish in size as they are driven into a board, the verse continues that these nails are planted. Plants grow, like the words of the sages grow as future generations apply them to new situations. The growing words can be confusing as their various interpretations gradually unfold, so we are advised to rely on the assemblies where divergent opinions are expressed and debated. In keeping with the principal of Talmudic interpretation that generally all of the reported opinions -- even though they may be contradictory -- are true. On some matters, the current state consists of conflict without resolution. Hence the final dimension of the metaphor is that all the diverse and contradictory opinions are given by one shepherd.