John Gill Commentary Amos 6:12

"Shall horses run upon the rock? will one plow [there] with oxen? that ye have turned justice into gall, and the fruit of righteousness into wormwood;" — Amos 6:12 (ASV)

Shall horses run upon the rocks? or will [one] plough [there] with oxen ? &c.] Will any man be so weak and foolish, to propose or attempt a race for horses upon rocks, where they and their riders would be in danger of breaking their necks? or would any man act so unwise a part, as to take a yoke of oxen to plough with them upon a rock, where no impression can be made? as vain and fruitless a thing it would be to attempt to bring such persons under a conviction of their sins, and to repentance for them, and reformation from them, who are given up to a judicial hardness of heart, like that of a rock, as are the persons described in the next clause; or as such methods with horses and oxen would be contrary to all the rules of reason and prudence, so as contrary a part do such persons act whose characters are next given, and there is no probability of bringing them to better sense and practice of things;

for you have turned judgment into gall, and the fruit of righteousness into hemlock ; that which would be beneficial to a nation, than which nothing is more so, as the exercise of justice, and judgment, into that which is bitter and pernicious to it, as injustice and oppression; see (Amos 5:7) .