Adam Clarke on Leviticus 19:35

Ye shall do no unrighteousness - Ye shall not act contrary to the strictest justice in any case, and especially in the four following, which properly understood, comprise all that can occur between a man and his fellow.

1. Judgment in all cases that come before the civil magistrate; he is to judge and decide according to the law.

2. Mete-Yard, במדה bammiddah, in measures of length and surface, such as the reed, cubit, foot, span, hand's breadth, among the Jews; or ell, yard, foot, and inch, among us.

3. Weight, במשכל bammishkal, in any thing that is weighed, the weights being all according to the standards kept for the purpose of trying the rest in the sanctuary, as appears from Exo 30:13; 1Chr 23:29; these weights were the talent, shekel, barleycorn, etc.

4. Measure, במשורה bammesurah, from which we derive our term. This refers to all measures of capacity, such as the homer, ephah, seah, hin, omer, kab, and log. See all these explained at Exo 16:16 (note).