וַאֲנִ֗י זֹ֣את בְּרִיתִ֤י אוֹתָם֙ אָמַ֣ר יְהוָ֔ה רוּחִי֙ אֲשֶׁ֣ר עָלֶ֔יךָ וּדְבָרַ֖י אֲשֶׁר־שַׂ֣מְתִּי בְּפִ֑יךָ לֹֽא־יָמ֡וּשׁוּ מִפִּיךָ֩ וּמִפִּ֨י זַרְעֲךָ֜ וּמִפִּ֨י זֶ֤רַע זַרְעֲךָ֙ אָמַ֣ר יְהוָ֔ה מֵעַתָּ֖ה וְעַד־עוֹלָֽם׃ (ס)
Quant à moi, dit l’Éternel, voici quel est mon pacte avec eux: mon inspiration qui repose sur toi et les paroles que j’ai mises en ta bouche, elles ne doivent point s’écarter de ta bouche, ni de la bouche de tes enfants, ni de celle des enfants de tes enfants, soit à présent, soit dans les temps futurs.
Akeidat Yitzchak
Devarim Rabbah in Parshat Ki Teytze is explicit about how the commandments accompany man wherever he is, since they apply to food, dress, habitation, commerce, etc., in short to every conceivable matter man may at any time be engaged in.
Derashot HaRan
There are several reasons for the Torah's relegating the resolution of doubts to the sages rather than to the prophets. First, it is obvious that prophets do not prophesy at all times. What, then, would we do on those days when the word of the L-rd was withheld from them? Furthermore, it was revealed and known to the L-rd that a time would come when our sins would "seal off vision and prophet"; and if the resolution of doubts were relegated to the prophets, what would we do when visions were suspended? We would "wander forth to seek the word of the L-rd and not find it." The Divine Wisdom, therefore, decreed that this function be relegated to the sages, who never departed and who never will depart from Israel, as we have been assured (Isaiah 59:21): "It shall not depart from the mouth of your children." In addition, the words of the prophet on which the Torah commands us to rely are not insusceptible of doubt, as will be explained. The Torah therefore chose to assign the resolution of doubts to the sages, who would have to conform to it [the Torah] with reason and proof, rather than to the prophets, whose words are confirmed only by signs, which signs themselves are susceptible of doubt.