(2) This is the ritual law that the LORD has commanded: Instruct the Israelite people to bring you a red cow without blemish, in which there is no defect and on which no yoke has been laid.
(2) זאת חקת התורה THIS IS THE ORDINANCE OF THE LAW — Because Satan and the nations of the world taunt Israel, saying, “What is this command and what reason is there for it”, on this account it (Scripture) writes (uses) the term חקה about it, implying: It is an enactment from before Me; you have no right to criticize it (Yoma 67b; cf. Midrash Tanchuma, Chukat 7).
(ח) שָׁאַל עוֹבֵד כּוֹכָבִים אֶחָד אֶת רַבָּן יוֹחָנָן בֶּן זַכַּאי, אִלֵּין עוֹבָדַיָּא דְּאַתּוּן עָבְדִין נִרְאִין כְּמִין כְּשָׁפִים, אַתֶּם מְבִיאִים פָּרָה וְשׂוֹרְפִין אוֹתָהּ וְכוֹתְּשִׁין אוֹתָהּ וְנוֹטְלִין אֶת אַפְרָהּ וְאֶחָד מִכֶּם מִטַּמֵּא לְמֵת, מַזִּין עָלָיו שְׁתַּיִם וְשָׁלשׁ טִפִּין וְאַתֶּם אוֹמְרִים לוֹ טָהַרְתָּ. אָמַר לוֹ לֹא נִכְנְסָה בְּךָ רוּחַ תְּזָזִית מִיָּמֶיךָ, אָמַר לוֹ לָאו. רָאִיתָ אָדָם שֶׁנִּכְנְסָה בּוֹ רוּחַ תְּזָזִית, אָמַר לוֹ הֵן, אָמַר לוֹ וּמָה אַתֶּם עוֹשִׂין לוֹ, אָמַר לוֹ מְבִיאִין עִקָּרִין וּמְעַשְׁנִין תַּחְתָּיו וּמַרְבִּיצִים עָלֶיהָ מַיִם, וְהִיא בּוֹרַחַת. אָמַר לוֹ יִשְׁמְעוּ אָזְנֶיךָ מַה שֶּׁאַתָּה מוֹצִיא מִפִּיךָ, כָּךְ הָרוּחַ הַזּוֹ, רוּחַ טֻמְאָה, דִּכְתִיב (זכריה יג, ב): וְגַם אֶת הַנְּבִיאִים וְאֶת רוּחַ הַטֻּמְאָה אַעֲבִיר מִן הָאָרֶץ, מַזִּין עָלָיו מֵי נִדָּה וְהוּא בּוֹרֵח. לְאַחַר שֶׁיָּצָא אָמְרוּ לוֹ תַּלְמִידָיו, רַבֵּנוּ, לָזֶה דָּחִית בְּקָנֶה, לָנוּ מָה אַתָּה אוֹמֵר, אָמַר לָהֶם חַיֵּיכֶם, לֹא הַמֵּת מְטַמֵּא וְלֹא הַמַּיִם מְטַהֲרִין, אֶלָּא אָמַר הַקָּדוֹשׁ בָּרוּךְ הוּא חֻקָּה חָקַקְתִּי גְּזֵרָה גָּזַרְתִּי אִי אַתָּה רַשַׁאי לַעֲבֹר עַל גְּזֵרָתִי, דִּכְתִיב: זֹאת חֻקַּת הַתּוֹרָה.
(8) A pagan asked Rabbi Yochanan ben Zakkai, "These rituals you do, they seem like witchcraft! You bring a heifer, burn it, crush it up, and take its ashes. [If] one of you is impure by the dead [the highest type impurity], 2 or 3 drops are sprinkled on him, and you declare him pure?!" He said to him, "Has a restless spirit ever entered you?" He said to him, "No!" "Have you ever seen a man where a restless spirit entered him?" He said to him, "Yes!" [Rabbi Yochanan ben Zakkai] said to him, "And what did you do for him?" He sad to him, "We brought roots and made them smoke beneath him, and pour water and it flees." He said to him, "Your ears should hear what leaves from your mouth! The same thing is true for this spirit, the spirit of impurity, as it is written, (Zachariah 13:2) "Even the prophets and the spirit of impurity will I remove from the land." They sprinkle upon him purifying waters, and it [the spirit of impurity] flees." After he left, our rabbi's students said, "You pushed him off with a reed. What will you say to us?" He said to them, "By your lives, a dead person doesn't make things impure, and the water doesn't make things pure. Rather, God said, 'I have engraved a rule, I have decreed a decree (chukah chakakti, gezeira gazarti), and you have no permission to transgress what I decreed, as it says "This is a chok (rule) of the Torah."
If we were henceforth to designate all “commandments pertaining to the relations between man and God” as minhagim or “folkways,” we would accomplish a twofold purpose. First, we would convey the thought that they should not be dealt with in a legalistic spirit, a spirit that often gives rise to quibbling and pettifogging. They should be dealt with as the very stuff of Jewish life, which should be experienced with spontaneity and joy, and which can be modified as circumstances require. Second, we would convey the implication that not only should as many “commandments” or folkways as possible be retained and developed, but that Jewish life should be stimulated to evolve new and additional folkways. Folkways are the social practices by which a people externalizes the reality of its collective being.
Rabbi Mordecai Kaplam, Judaism as a Civilization, p. 432
In carrying out a sacred deed, we unseal the wells of faith...A Jew is asked to take a leap of action rather than a leap of thought [or faith]. He is asked to surpass his needs, to do more than he understands in order to understand more than he does. In carrying out the word of the Torah he is ushered into the presence of spiritual meaning. Through the ecstasy of deeds he learns to be certain of the hereness of God. Right living is a way to right thinking.
Rabbi Abraham Joshua Heschel, God in Search of Man, p. 282-283