אֶת־יְהוָ֥ה הֶאֱמַ֖רְתָּ הַיּ֑וֹם לִהְיוֹת֩ לְךָ֨ לֵֽאלֹהִ֜ים וְלָלֶ֣כֶת בִּדְרָכָ֗יו וְלִשְׁמֹ֨ר חֻקָּ֧יו וּמִצְוֺתָ֛יו וּמִשְׁפָּטָ֖יו וְלִשְׁמֹ֥עַ בְּקֹלֽוֹ׃
A SEÑOR has ensalzado hoy para que te sea por Dios, y para andar en sus caminos, y para guardar sus estatutos y sus mandamientos y sus derechos, y para oir su voz:
Rashi
האמרה, האמירך are words for the meaning of which there is no decisive proof in Scripture. It seems to me, however, that they are expressions denoting “separation” and “selection”: “You have singled Him out from all strange gods to be unto you as God — and He on His part, has singled you out from the nations on earth to be unto Him a select people”. [As far as this meaning is concerned I have found a parallel (lit., a witness) to it where it bears the meaning “glory”, as in (Psalms 94:4): “All wrongdoers glory in themselves”].
Ibn Ezra
The Hebrew word bespoke carries connotations of exaltation. Compare, “in the top of the uppermost bough” [Isaiah 17: 6]. The Spaniard Rabbi Y e hudah HaLevy — may he be for us a light from above! — cleverly explained how the word is related to the verb “to say”: the sense of the passage is that you have done all that is proper, to the point that you cause other people to say “He will be your God”; and He will likewise act toward you so as to cause you to say that you will be His treasured people. According, the verb “to bespeak” takes both a direct and an indirect object.
Ramban
THOU HAST AVOUCHED THE ETERNAL THIS DAY. The meaning thereof is: “Since you have accepted the entire Torah upon yourselves with all its interpretations, details, and new promulgations, you have thus magnified G-d and exalted Him, that He alone will be your G-d; you will in no way avow another god.”