Exode 20:1

And Elokim spoke: There is no (mention of) Elokim but as a judge; Because there are sections (verses) in the Torah that a person that performs them receives merit (reward), and should he refrain from doing them he does not receive punishment, it might be thought, that this also applies to the 10 commandments. To teach us otherwise the Torah says: and Elokim spoke - (the usage of the name Elokim means) a judge that punishes (Mechilta).

And the Lord spake all these words, saying:

Rabbi Yehuda HaLevi, may His memory be an honor, asked me why it mentioned, "I am the Lord, your God, that took you out of the land of Egypt," and it did not state, "that made the heavens and the earth and I made you." And this was my answer to him: Know that the levels of people’s faith, in which they believe in the glorious God in their hearts, is not equal. As the masses believe that which was heard by their ears, that their Master told them this. And above them are those that saw it written in the words of the Torah that God gave to Moshe. And if a heretic comes to challenge that there is no God, they will place their hands on their mouths, as they will not know [what] to answer. And the one whose heart has elevated him to learn the sciences – which are like stairs to rise up upon to the place of his desire – will recognize the work of God in the patterns and the plants and the animals, and in his own human body - that he will know the function of each limb, according to its development, and why it is [made] in such a pattern. And his heart will elevate him afterwards to know the matters of the planets, that they are the works of God in the intermediate world – that he should stand and know the time of when the sun should appear or the moon and how much [of that time] the sun will appear. And he will also know why the moon appears and Who caused it [to do so]. And all of this, he will know with clear proofs that have no doubt. And from [these] ways of God, the enlightened one will know God. And so did Moshe say (Exodus 33:13), “show me Your ways and I will know You.” And behold the glorious God mentioned in the first of the statements (of the Ten Commandments), “I am the Lord, your God” – and this can only be understood by someone who is an outstanding sage. As I have already explained in Parshat Veeleh HaShemot (Ibn Ezra on Exodus 3:15) that this God is alone and He exists without change and there is none besides Him who is eternal and there is none like Him that 'dwells from the beginning always.' And He supports the higher world with His power and the intermediary world with the power of God, and His holy angels that are in the higher world. And this lowly world that we are in, He supports with the power of God and with the power of the two higher worlds. And behold, the statement, “I am the Lord, your God,” suffices for the enlightened one in every nation. As [while] only Israel concedes to the making of the heavens and the earth which …

וידבר אלוקים, after Moses had completed warning the people G’d proceeded to utter all these commandments, as we know from the testimony of Moses in Deuteronomy 5,18 את כל הדברים האלה דבר ה' אל כל קהלכם בהר, “all these words the Lord spoke to your assembled ranks from the Mountain.”

את כל הדברים האלה לאמר, “all of these words.” The word לאמר teaches that the entire Ten Commandments would be part of a single utterance, something that it is impossible for the mouth of a human being to do. Seeing that this was so, why does the Torah write it as if it had been a number of separate utterances, i.e. אנכי ה' אלוקיך, לא יהיה לך, etc.? This shows that Moses repeated each of the commandments. (Mechilta, Yitro bachodesh, section 4) This appears hard to understand, how did the author of the Mechilta think that Moses contributed to our understanding the Ten Commandments by repeating, or trying to repeat what G–d had done? What was meant is that Moses by adding the cantillations, enabled the people to understand every word. A different interpretation of this Mechilta by Rabbi Baruch: Moses in his repeating the utterance separated between what is the first verse in our chumashim, and the second verse by taking a breath, although basically the two verses are part of the same commandment. Proof of that is the fact G–d is speaking in the first person repeatedly, i.e. “I have taken you out of Egypt; My presence; I am the Lord your G–d; “the ones who hate Me.” “The ones who love Me.” All the other parts of the Ten Commandments are addressed to “you.” This is why the Talmud in tractate Makkot folio 24 states that the first two Commandments were uttered by G–d personally. The Talmud explains that although G–d uttered all Ten Commandments, the people could only hear and understand G–d as speaking the first two commandments. [They had asked Moses to interpret the remainder for them. Ed]