The Ten Commandments

This is my best guess as to what must have happened. The Torah grew by incorporating what was previously just commentary. The ten commandments started off succinctly:

אָנֹכִי יְהוָה אֱלֹהֶיךָ, אֲשֶׁר הוֹצֵאתִיךָ מֵאֶרֶץ מִצְרַיִם מִבֵּית עֲבָדִים
וְעָשׂוּ לִי, מִקְדָּשׁ; וְשָׁכַנְתִּי, בְּתוֹכָם
לֹא תִשָּׂא אֶת-שֵׁם-יְהוָה אֱלֹהֶיךָ, לַשָּׁוְא
זָכוֹר אֶת-יוֹם הַשַּׁבָּת, לְקַדְּשׁוֹ
כַּבֵּד אֶת-אָבִיךָ, וְאֶת-אִמֶּךָ
לֹא תִרְצָח
לֹא תִנְאָף
לֹא תִגְנֹב
לֹא-תַעֲנֶה בְרֵעֲךָ עֵד שָׁקֶר
לֹא תַחְמֹד, בֵּית רֵעֶך

Subsequently, the commentaries were incorporated in the text, thus producing the version in Parashat Vayechan of the Torah Kedumah. Today's version of the Torah resulted after new commentaries were added to וְעָשׂוּ לִי, מִקְדָּשׁ; וְשָׁכַנְתִּי, בְּתוֹכָם, and to וְאַתָּה תְּצַוֶּה אֶת-בְּנֵי יִשְׂרָאֵל, וְיִקְחוּ אֵלֶיךָ שֶׁמֶן זַיִת זָךְ כָּתִית--לַמָּאוֹר לְהַעֲלֹת נֵר, תָּמִיד, and were incorporated. The commentaries were very elaborate and were inserted as separate "Parashot," Parashat Teruma for וְעָשׂוּ לִי, מִקְדָּשׁ; וְשָׁכַנְתִּי, בְּתוֹכָם and its commentary, Parashat Tetzavei for וְאַתָּה תְּצַוֶּה אֶת-בְּנֵי יִשְׂרָאֵל, וְיִקְחוּ אֵלֶיךָ שֶׁמֶן זַיִת זָךְ כָּתִית--לַמָּאוֹר לְהַעֲלֹת נֵר תָּמִיד, and its commentary. That left the earlier commentary to וְעָשׂוּ לִי, מִקְדָּשׁ; וְשָׁכַנְתִּי, בְּתוֹכָם, a dangling "orphan" leading to some textual complications. Moreover, Parashat Mishpatim, was moved a bit to "make place" for Parashat Teruma, and Parashat Tetzavei, and to mask the editing. Moreover, the "commentary" of זָכוֹר אֶת-יוֹם הַשַּׁבָּת, לְקַדְּשׁוֹ was improved by the addition of a reference to the six days of Creation.

Finally, note that the second commandment has disappeared, to Parshat Teruma. The commentary to the first commandment, or the commentary of the last commandment, is counted instead. It is possible that the first two of the original commandments were counted as one,

אָנֹכִי יְהוָה אֱלֹהֶיךָ, אֲשֶׁר הוֹצֵאתִיךָ מֵאֶרֶץ מִצְרַיִם מִבֵּית עֲבָדִים וְעָשׂוּ לִי, מִקְדָּשׁ; וְשָׁכַנְתִּי, בְּתוֹכָם

with the perush that they will make the Mishkan, as slaves. What is then the tenth commandment, one that was actually heard?

וְאַתָּה תְּצַוֶּה אֶת-בְּנֵי יִשְׂרָאֵל, וְיִקְחוּ אֵלֶיךָ שֶׁמֶן זַיִת זָךְ כָּתִית--לַמָּאוֹר לְהַעֲלֹת נֵר תָּמִיד

We learn from this what we shall do in the Mishkan.

Time has come to return to the source, to identify and remove the commentaries of Bayit Sheni, and to remove the commentaries of Bayit Rishon as well. That is why the research of Torah is so important. It reveals the Source.