(35) You shall not falsify measures of length, weight or capacity. (36) You shall have an honest balance, honest weights, an honest ephah, and an honest hin. I am the Lord your God, who brought you out of the land of Egypt.
Medieval Commentaries
(רש’’י ( 1040-1105 France/צרפת
לא תעשו עול במשפט: אם לדין, הרי כבר נאמר לא תעשו עול במשפט (פסוק טו), ומהו משפט השנוי
כאן, הוא המדה והמשקל והמשורה. מלמד שהמודד נקרא דיין, שאם שיקר במדה הרי הוא כמקלקל את הדין וקרוי עול, שנאוי, ומשוקץ, חרם ותועבה. וגורם לחמשה דברים האמורים בדיין מטמא את הארץ, ומחלל את השם, ומסלק את השכינה, ומפיל את ישראל בחרב, ומגלה אותם מארצם.
You shall not falsify: If we are dealing with litigation, it was already stated in [the Torah] "You shall not commit injustice in judgment" (Lev. 19:15). So what is the different "judgment" here [in this mitzvah]? It refers to measures, weights and liquid measures. This teaches that the one who measures out something is called a judge, since if he lies regarding the measure of something, behold he is like one who perverts justice and he is called perverse, hated, disgusting, fit for destruction and an abomination. And he causes the five stated things regarding a (corrupt) judge that impurifies the land and desecrates the Name of God: drives away the Shechina, causes Israel to fall by the sword and exiles them from their land.
במדה: זו מדת הארץ
Of length: This refers to measurement of the land (measurement of length or area of land)
במשקל: כמשמעו
Of weight: This refers to its obvious meaning.
ובמשורה: היא מדת הלח
Or capacity: This refers to liquid measures (volume).
אשר הוצאתי אתכם: על מנת כן. דבר אחר אני הבחנתי במצרים בין טפה של בכור לטפה שאינה של בכור, ואני הנאמן להפרע ממי שטומן משקלותיו במלח להונות את הבריות שאין מכירים בהם.
Who took you out: On this condition (I freed you to observe these mitzvot). Another explanation: I distinguished in Egypt between the drop of sperm that led to a firstborn and the drop of sperm that did not lead to a firstborn, (therefore) I am faithful to exact payment from whoever buries his weights in salt (altering the weight) to defraud people who do not recognize them.
(לה) לא תעשו עול במשפט במדה במשקל ובמשורה. וזה כי בהיות בכלל אונאה גם אונאת ממון הזהיר מן האונאה הכללית לאזרח ולגר והם מדות הלח והיכש ומשקלותם:
(35) You shall not falsify measures of length, weight or capacity. This is because the term אונאה, unfair dealings, also includes unfair business practices, the Torah issues a general prohibition concerning this addressed to the locally born Jew and the convert, or stranger. The words used include measures for measuring liquids, dry matters, as well as the use of (deceptive) weights. (Sforno, Italy 1475-1550)
And if you surely sell to your neighbor, or buy from your neighbor’s hand, you shall not wrong one another (literally ׳brother’).
(יג) לֹֽא־יִהְיֶ֥ה לְךָ֛ בְּכִֽיסְךָ֖ אֶ֣בֶן וָאָ֑בֶן גְּדוֹלָ֖ה וּקְטַנָּֽה׃ (ס) (יד) לֹא־יִהְיֶ֥ה לְךָ֛ בְּבֵיתְךָ֖ אֵיפָ֣ה וְאֵיפָ֑ה גְּדוֹלָ֖ה וּקְטַנָּֽה׃ (טו) אֶ֣בֶן שְׁלֵמָ֤ה וָצֶ֙דֶק֙ יִֽהְיֶה־לָּ֔ךְ אֵיפָ֧ה שְׁלֵמָ֛ה וָצֶ֖דֶק יִֽהְיֶה־לָּ֑ךְ לְמַ֙עַן֙ יַאֲרִ֣יכוּ יָמֶ֔יךָ עַ֚ל הָֽאֲדָמָ֔ה אֲשֶׁר־יְהוָ֥ה אֱלֹהֶ֖יךָ נֹתֵ֥ן לָֽךְ׃ (טז) כִּ֧י תוֹעֲבַ֛ת יְהוָ֥ה אֱלֹהֶ֖יךָ כָּל־עֹ֣שֵׂה אֵ֑לֶּה כֹּ֖ל עֹ֥שֵׂה עָֽוֶל׃ (פ)
(13) You shall not have in your pouch alternate weights, larger and smaller. (14) You shall not have in your house alternate measures, a larger and a smaller. (15) You must have completely honest weights and completely honest measures, if you are to endure long on the soil that the Lord your God is giving you. (16) For everyone who does those things, everyone who deals dishonestly, is abhorrent to the Lord your God.
(טו) למען יאריכו ימיך. כי זה ידוע כי כל מלכות צדק תעמוד כי הצדק כבנין והעיוות כהריסו' ברגע יפול הקיר
In order to lengthen your days. For it is known that a just kingdom will stand because justice is like a building and injustice is like its destruction the moment the wall falls. (Ibn Ezra, 1089, Spain-1167, France)
(טז) כל עושה אלה. איפה ואיפה אבן ואבן והכלל כל עושה עול בפה ובמעשה בסתר או בגלוי
Anyone who does these things. Efah and Efah, stone and stone (of different measurements), and the rule is anyone who deals unjustly with words and deed in secret or transparently.
רש’’י Rashi
גדולה וקטנה: גדולה שמכחשת את הקטנה, שלא יהא נוטל בגדולה ומחזיר בקטנה
Big and small: This big stone (used to weigh merchandise in business) is not consistent with the small one [You must not have two weights that appear to be the same but are actually unequal] so that you purchase with the larger weight (cheating seller) and sell with the smaller weight (cheating customer) (Sifrei 25:162).
לא יהי לך: עם עשית כן לא יהיה לך כלום
It shall not be to you: If you do this, you shall have nothing (Sifrei 25:162)
אבן שלמה וצדק יהיה לך: אם עשית כן יהיה לך הרבה
If you have a full and honest weight: If you do this, you will have much (Sifrei 25:162).
(יז) זָכ֕וֹר אֵ֛ת אֲשֶׁר־עָשָׂ֥ה לְךָ֖ עֲמָלֵ֑ק בַּדֶּ֖רֶךְ בְּצֵאתְכֶ֥ם מִמִּצְרָֽיִם׃ (יח) אֲשֶׁ֨ר קָֽרְךָ֜ בַּדֶּ֗רֶךְ וַיְזַנֵּ֤ב בְּךָ֙ כָּל־הַנֶּחֱשָׁלִ֣ים אַֽחַרֶ֔יךָ וְאַתָּ֖ה עָיֵ֣ף וְיָגֵ֑עַ וְלֹ֥א יָרֵ֖א אֱלֹהִֽים׃ (יט) וְהָיָ֡ה בְּהָנִ֣יחַ יְהוָ֣ה אֱלֹהֶ֣יךָ ׀ לְ֠ךָ מִכָּל־אֹ֨יְבֶ֜יךָ מִסָּבִ֗יב בָּאָ֙רֶץ֙ אֲשֶׁ֣ר יְהוָֽה־אֱ֠לֹהֶיךָ נֹתֵ֨ן לְךָ֤ נַחֲלָה֙ לְרִשְׁתָּ֔הּ תִּמְחֶה֙ אֶת־זֵ֣כֶר עֲמָלֵ֔ק מִתַּ֖חַת הַשָּׁמָ֑יִם לֹ֖א תִּשְׁכָּֽח׃ (פ)
(17) Remember what Amalek did to you by the way as you came forth out of Egypt; (18) how he met you by the way, and smote the hindmost of you, all that were enfeebled in your rear, when you were faint and weary; and he feared not God. (19) Therefore it shall be, when the LORD your God has given you rest from all your enemies around in the land which the LORD your God gives you for an inheritance to possess it, that you shall blot out the remembrance of Amalek from under heaven; you shall not forget.
רש’’י: זכור את אשר עשה לך: אם שקרת במדות ובמשקלות הוי דואג מגרוי האויב, שנאמר (משלי יא א) מאזני מרמה תועבת ה', וכתיב בתריה בא זדון ויבא קלון:
Rashi
Remember what [Amalek] did to you: [The juxtaposition of these passages teaches us that] if you use fraudulent measures and weights, you should be worried about provocation from the enemy, as it is said: “Deceitful scales are an abomination of the Lord” (Prov. 11:1), after which the [next] verse continues,“When willful wickedness comes, then comes disgrace.” [That is, after you intentionally sin by using deceitful scales, the enemy will come to provoke you into war, and this will be a disgraceful matter to you]. — [Tanchuma 8]
You shall not render an unfair decision: do not favor the poor or show deference to the rich; judge your kinsman fairly.
And he chose a first part for himself, For there a portion of a ruler was reserved; And there came the heads of the people, He executed the righteousness of the LORD, And His ordinances with Israel.