Tzedek Tzedek Tirdof in Context
(יח) שֹׁפְטִ֣ים וְשֹֽׁטְרִ֗ים תִּֽתֶּן־לְךָ֙ בְּכָל־שְׁעָרֶ֔יךָ אֲשֶׁ֨ר יְהוָ֧ה אֱלֹהֶ֛יךָ נֹתֵ֥ן לְךָ֖ לִשְׁבָטֶ֑יךָ וְשָׁפְט֥וּ אֶת־הָעָ֖ם מִשְׁפַּט־צֶֽדֶק׃ (יט) לֹא־תַטֶּ֣ה מִשְׁפָּ֔ט לֹ֥א תַכִּ֖יר פָּנִ֑ים וְלֹא־תִקַּ֣ח שֹׁ֔חַד כִּ֣י הַשֹּׁ֗חַד יְעַוֵּר֙ עֵינֵ֣י חֲכָמִ֔ים וִֽיסַלֵּ֖ף דִּבְרֵ֥י צַדִּיקִֽם׃ (כ) צֶ֥דֶק צֶ֖דֶק תִּרְדֹּ֑ף לְמַ֤עַן תִּֽחְיֶה֙ וְיָרַשְׁתָּ֣ אֶת־הָאָ֔רֶץ אֲשֶׁר־יְהוָ֥ה אֱלֹהֶ֖יךָ נֹתֵ֥ן לָֽךְ׃ (ס)

(18) You shall appoint magistrates and officials for your tribes, in all the settlements that Adonai your God is giving you, and they shall govern the people with due justice. (19) You shall not judge unfairly: you shall show no partiality; you shall not take bribes, for bribes blind the eyes of the discerning and upset the plea of the just. (20) Justice, justice shall you pursue, that you may thrive and occupy the land that Adonai your God is giving you.

(א) צדק צדק תרדף. הַלֹּךְ אַחַר בֵּית דִּין יָפֶה (ספרי; סנהדרין ל"ב):

(1) צדק צדק תרדף Justice, justice shall you pursue — Seek out a good court.

(ב) למען תחיה וירשת. כְּדַאי הוּא מִנּוּי הַדַּיָּנִין הַכְּשֵׁרִים לְהַחֲיוֹת אֶת יִשְׂרָאֵל וּלְהוֹשִׁיבָן עַל אַדְמָתָן (ספרי):

(2) למען תחיה וירשת That you may thrive and occupy the land — The appointment of proper judges is sufficient to make Israel thrive and to establish them on their land.

How does Rashi (11th century France) understand Tzedek Tzedek Tirdof?

(א) צדק צדק. עם בעלי הריב ידבר וטעם שני פעמים לדבר צדק שירויח בו או יפסיד או פעם אחר פעם כל ימי היותך או לחזוק:

(1) Justice, justiceThis is addressed to each of the contending parties. The repetition of "justice" implies that they should pursue a just result whether it brings them profit or loss, or perhaps that they should continue to pursue justice time after time, as long as they live. Or it may simply be for emphasis.

How does Ibn Ezra (12th century Spain) understand Tzedek Tzedek Tirdof ?

Justice, justice... The great Mussar rabbis say that if one hastens to give tzedakah it is worth double, as if one gave tzedakah twice. Tzedek tzedek - it will be considered as two tzedakahs, if "you pursue" it, if you try to give it as soon as possible.

Hida (18th century Palestine & Western Europe, North Africa)

Justice, justice you shall pursue...With justice, you shall pursue justice. Even the pursuit of justice must employ only just means, and not falsehood.

R' Simhah Bunim of Pshischa (18th century Poland)

Justice, justice you shall pursue...Justice alone is not enough, because there are many types of justice, just as there are many kinds of truth. Every regime has its own justice. The Torah, therefore, stresses, "Justice justice you shall pursue," namely the musar (ethic) of justice, where both the means and the end are just.

Derashot El Ami (19th-20th century Poland & Palestine)