Halakhah for Deuteronomy 4:35
אַתָּה֙ הָרְאֵ֣תָ לָדַ֔עַת כִּ֥י יְהוָ֖ה ה֣וּא הָאֱלֹהִ֑ים אֵ֥ין ע֖וֹד מִלְבַדּֽוֹ׃
Unto thee it was shown, that thou mightiest know that the LORD, He is God; there is none else beside Him.
Arukh HaShulchan
The foundation of Torah and the pillar of the divine service is to know that there is one God. who is singular and unique, and that He created the Worlds(i.e this world and the next world), and that he is constantly watching us. If, God forbid, he suddenly stopped watching and guiding the world even for a moment, it would revert to chaos and disorder. This is the essence of what is stated: (Deuteronomy 6:4) 'Listen, oh Israel, Hashem, your God, is One'.
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