מִצְוַת עֲשֵׂה הָרִאשׁוֹנָה

The first positive commandment is,

ובִלְשׁוֹן הָרַמְבַּ"ם "לֵידַע שֶׁיֵּשׁ שָׁם מָצוּי רִאשׁוֹן מַמְצִיא כָל נִמְצָא כו

according to the wording of Rambam, “To know that there is a Primary Being who brings into being all existence…

וִידִיעַת דָּבָר זֶה מִצְוַת עֲשֵׂה וּכְמוֹ שֶׁכָּתוּב אָנֹכִי ה' אֱלוֹקֶיךָ

Knowing this concept [fulfills] a positive commandment, as it is written, ‘I am G‑d, your L‑rd.’ “

הִיא מִצְוַת הַמּוֹחַ וְהַשֵּׂכֶל

This mitzvah centers on the brain and the mind.

וְהַיְנוּ דַהֲגַם דְּכָל אֶחָד וְאֶחָד מִיִּשְׂרָאֵל הוּא מַאֲמִין בַּה' בֶּאֱמוּנָה פְּשׁוּטָה

Although every single Jew believes in G‑d with simple faith

וּלְבָבוֹ תָּמִים עִם ה

and his heart is wholly and artlessly with G‑d,

חוֹבַת הַמּוֹחַ וְהַשֵּׂכֶל לְהָבִיא אֱמוּנָה זוֹ בִּידִיעָה וַהֲשָׂגָה

the brain and mind are obligated to bring this faith to the point of knowledge and comprehension.

"וְזֶהוּ "לֵידַע שֶׁיֵּשׁ שָׁם מָצוּי רִאשׁוֹן

This is what is meant by the obligation “to know that there is a Primary Being.”

עֶר זאָל דאָס וִויסעֶן בַּהֲשָׂגָה וַהֲבָנָה דַוְקָא

One must know this in terms of comprehension and understanding,

וּכְמוֹ שֶׁכָּתוּב דַּע אֶת אֱלֹקֵי אָבִיךָ וְעָבְדֵהוּ בְּלֵב שָׁלֵם, וּכְתִיב וְיָדַעְתָּ הַיּוֹם גו

as it is written, “Know the G‑d of your father and serve Him wholeheartedly.” It is likewise written, “And you shall know this day… [that G‑d is the L‑rd].”

Text and Translation courtesy of Sichos in English