Mishneh Torah — Transmission of the Oral Law מסירת תורה שבעל פה, Chapter 1

אָז לֹא אֵבוֹשׁ, בְּהַבִּיטִי אֶל כָּל מִצְו‍ֹתֶיךָ:כָּל הַמִּצְווֹת שֶׁנִּתְּנוּ לוֹ לְמֹשֶׁה בְּסִינַי – בְּפֵרוּשָׁן נִתְּנוּ, שֶׁנֶּאֱמָר "וְאֶתְּנָה לְךָ אֶת־לֻחֹת הָאֶבֶן, וְהַתּוֹרָה וְהַמִּצְוָה" (שמות כד, יב): "תּוֹרָה", זוֹ תּוֹרָה שֶׁבִּכְתָב; וּ"מִצְוָה", זֶה פֵּרוּשָׁהּ. וְצִוָּנוּ לַעֲשׂוֹת הַתּוֹרָה, עַל פִּי הַמִּצְוָה. וּמִצְוָה זוֹ, הִיא הַנִּקְרֵאת תּוֹרָה שֶׁבְּעַל פֶּה.

The Rambam's Introduction and appears to be a printer's addition. Note Hilchot Shechitah 1:4, where the Rambam refers to "...the Oral Law, which is called `the mitzvah,' as we explained in the beginning of this text."By referring to these passages as "the beginning" of the text and not "the introduction to the text," the Rambam implies that the subject matter contained in these passages is an essential part of the Mishneh Torah and not merely an author's preamble. to the Mishneh Torah"In the name of God, Lord of the world" it is included in the manuscript editions. It is also found at the beginning of the Rambam's other works, the Commentary on the Mishnah, Sefer HaMitzvot, and the Guide to the Perplexed. The Rambam's intention is to clarify that he does not see this work as an expression of his individual efforts alone, but that it was composed "In the name of God, the Lord of the world." (Genesis 21:33)"Then I will not be ashamed when I gaze at all Your mitzvot" by quoting an appropriate verse from the Bible. It is possible to explain that he chose this verse for the introduction to the entire text in reply to objections he knew would arise to the Mishneh Torah. The Rambam's conception of his work as "a compilation of the entire Oral Law" would not be acceptable to many. Therefore, he begins by emphasizing that his actions were not presumptuous. There is no need for him to be "ashamed" at taking such a step. Since he can "gaze at all Your mitzvot" - i.e., has the knowledge of the entire Oral Law - he is obligated to try to communicate that knowledge to others, as stated in Hilchot Talmud Torah 5:4 (Yayin Malchut). (Psalms 119:6).The mitzvot given to Moses at Mount Sinai were all given together with their explanations, as implied by [Exodus 24:12]: "And I will give you the tablets of stone, the Torah, and the mitzvah.""The Torah" refers to the Written Law; "the mitzvah," to its explanation. [God] commanded us to fulfill "the Torah" according to [the instructions of] "the mitzvah." (Discourse 3, Chapter 3), where Rav Sa'adiah Gaon explains at length how the oral tradition is necessary to understand how to fulfill the mitzvot "The mitzvah" is called the Oral Law.