In Amos 5:14,15 where it says maintain "justice in the courts" WHAT EXACTLY WAS THAT? IT HAD TO BE DIFFERENT THAN OUR COURTS.?

It is reckoned (Ezech. 18:8) among other works of a good and just man, that "he hath executed true judgment between man and man." But judicial precepts are so called from "judgment." Therefore it seems that the judicial precepts were those which directed the relations between man and man.

I answer that, As is evident from what we have stated above (Q[95], A[2] ; Q[99], A[4]), in every law, some precepts derive their binding force from the dictate of reason itself, because natural reason dictates that something ought to be done or to be avoided. These are called "moral" precepts: since human morals are based on reason. At the same time there are other precepts which derive their binding force, not from the very dictate of reason (because, considered in themselves, they do not imply an obligation of something due or undue); but from some institution, Divine or human: and such are certain determinations of the moral precepts. When therefore the moral precepts are fixed by Divine institution in matters relating to man's subordination to God, they are called "ceremonial" precepts: but when they refer to man's relations to other men, they are called "judicial" precepts. Hence there are two conditions attached to the judicial precepts: viz. first, that they refer to man's relations to other men; secondly, that they derive their binding force not from reason alone, but in virtue of their institution.

what do you mean it has to be different? it was talking about a court of law; granted not necessarily a US court

justice in the courts of Israel and Judah