Ye shall do no unrighteousness in judgment. If you take the word judgment in its strict sense, this will be a special precept, that judges should faithfully do justice to all, and not subvert just causes from favor or ill-will. But since the word mspht, mishpat, often means rectitude, it will not be unsuitable to suppose that all iniquities contrary to integrity are generally condemned; and that he afterwards proceeds to particular cases, which he adverts to elsewhere, where he enumerates the most injurious thefts of all, and such as involve the grossest violation of public justice. For the corruption which tends to the subversion of judgments, or, by undermining rectitude, vitiates all contracts, leaves nothing in security; whilst deception in weights and measures destroys and sweeps away all legitimate modes of dealing. Now, if the laws of buying and selling are corrupted, human society is in a manner dissolved; so that he who cheats by false weights and measures, differs little from him who utters false coin: and consequently one, who, whether as a buyer or seller, has falsified the standard measures of wine or corn, or anything else, is accounted criminal. By the laws of Rome, [1] he is condemned to a fine of double the amount; and by a decree of Adrian, he is to be banished to an island. It is not, therefore, without reason that Solomon reiterates this decree, that he may fix it the deeper in the hearts of all. (Proverbs 20:10, 23.) But although this pestilent sin is by no means to be endured, but to be severely punished, still God, even if legal punishments be not inflicted, summons men's consciences before His tribunal, and this he does both by promises and threats. A just weight (He says) and a just measure shall prolong a man's life; but he who has been guilty of deception in them, is an abomination before me. Length of life, indeed, has only a figurative connection with just weights and measures: but, because the avaricious, in their pursuit of dishonest gain, are too devoted to this transitory life, God, in order to withhold His people from this blind and impetuous covetousness, promises them long life, if they keep themselves from fraud and all knavish dealings. We perceive from the conclusion, that, not in this respect only, but in all our affairs, those trickeries are condemned, by which our neighbors are defrauded. For, after God has said that He abominates "all that do such things," He adds immediately by way of explanation, "all that do unrighteously." We see, then, that He sets Himself against all evil and illicit arts of gain.

Footnotes

1 - Modest. 1. penult, ad legem Corn. de fals. -- C. This law is to be found in Digest. 48, tit. 11, De falsis, 32, "Si venditor mensuras publice probatas vini, frumenti, vel cujuslibet rei, aut emptor corruperit, dolove malo fraudem fecerit, quanti ea res est, ejus dupli condemnatur. Decretoque Divi Hadriani praeceptum est in insulam eos relegari, qui pondera, aut mensuras falsassent."

The ephah is here taken as the standard of dry measure, and the bin (see Exodus 29:40 note) as the standard of liquid measure. Of the two very different estimates of the capacities of these measures, the more probable is that the ephah did not hold quite four gallons and a half, and the hin not quite six pints. The log was a twelfth part of the hin Leviticus 14:10.

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 Exodus 30:13; 1-Chronicles 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 Exodus 16:16 (note).

Ye shall do no unrighteousness in judgment, in (o) meteyard, in weight, or in measure.
(o) As in measuring the ground.

Ye shall do no unrighteousness in judgment,.... This is repeated from Leviticus 19:15; and in order to lead on to some other laws and instructions; though Aben Ezra thinks this is said in connection with the preceding words, and in reference to the stranger, agreeably to Deuteronomy 1:16; but Jarchi refers it to what follows concerning weights and measures, and observes, that a measurer is a judge; and if he acts deceitfully, he perverts judgment, and does that which is detestable and abominable, and is the cause of the five following things said of a judge; he defiles the land, and profanes the name of God, and causes the Shechinah or divine Majesty to remove, or causes Israel to fall by the sword, or carries them captive out of their land:
in meteyard, in weight, or in measure; the first of these, according to Jarchi, signifies the measure of land, of fields, &c. and so likewise of anything that is measured, not only by the rod or line, but by the yard or ell, as cloth and other things, whether broad or narrow, that are measured in their length; and the second may respect the weight of all sorts of things that are weighed in scales, as money in former times, as well as various sorts of goods; and the last has respect to the measure of both dry and liquid things, by the bushel, peck, quart, pint, &c.

As a universal rule, they were to do no wrong in judgment (the administration of justice, Leviticus 19:15), or in social intercourse and trade with weights and measures of length and capacity; but to keep just scales, weights, and measures. On ephah and hin, see at Exodus 16:36 and Exodus 29:40. In the renewal of this command in Deuteronomy 25:13-16, it is forbidden to carry "stone and stone" in the bag, i.e., two kinds of stones (namely, for weights), large and small; or to keep two kinds of measures, a large one for buying and a small one for selling; and full (unadulterated) and just weight and measure are laid down as an obligation. This was a command, the breach of which was frequently condemned (Proverbs 16:11; Proverbs 20:10, Proverbs 20:23; Amos 8:5; Micah 6:10, cf. Ezekiel 45:10).

In mete - yard - In the measuring of lands, or dry things, as cloth, ribband. In measure - In the measuring liquid or such dry things as are only contigious, as corn or wine.