Exodus 20:16

And they said to Mosheh, Speak thou with us, and we can hear; but let it not be spoken with us any more from before the Lord, lest we die.

They said to Moshe. The kohanim and the leaders of the tribes spoke with Moshe at the conclusion of the proclaiming of the Ten Commandments. This experience was so terrifying that they thought that if Hashem would speak with them any further they might die, to which Moshe responded, “Do not be afraid, etc.”

BUT LET NOT G-D SPEAK WITH US. The Rabbi [Moshe ben Maimon] noted in the Moreh Nebuchim that Onkelos translated but let not G-d speak with us as, “Let not aught be spoken to us from before G-d.” However, he did not paraphrase in [a similar manner] in other such places, for he translated literally, And G-d spoke all these words, and so also in all places where it says, And the Eternal spoke unto Moses!, 6:10, etc. Now the reason for Onkelos’ paraphrasing it here, [according to Maimonides], was that even though all Israel heard the first commandment, their capacity for comprehending it was unlike that of Moses our teacher., for Moses achieved the highest comprehension humanly possible in prophecy, and therefore he received the word of G-d directly. But where the people were concerned, since their comprehension was of a far lesser degree, Onkelos translated, “from before G-d.” But if [Maimonides’ opinion is correct], why did Onkelos translate literally, For I have talked with you from heaven, when he should have rendered it, “It was spoken to you from before Me!” Similarly in the Book of Deuteronomy, he translated literally: These words the Eternal spoke unto all your assembly, [and he did not paraphrase it]! So also he translated literally their words, and we have heard His Voice,, Verse 21. which he rendered as follows: “we have heard the voice of His word; this day we have seen that G-d speaks with man!” Likewise he translated literally, The Eternal spoke with you face to face., Verse 5. Moreover, [with reference to Moses] he translated, And G-d answered him by a voice as “and from before G-d he was answered by a voice!” [Here Onkelos paraphrased it with regard to Moses himself, which according to Maimonides he should have translated literally!] In fact, such usage already occurs in the Torah with reference to Moses himself! Thus: And he heard the Voice speaking, not m’dabeir (speaking), and Rashi markedly comments that it means “uttering itself” and Moses heard it of himself. It is out of reverence for G-d that this expression is used. unto him, which Onkelos translated as “being spoken.” So also in the verse, The pillar of the cloud descended, and stood at the door of the Tent, and He spoke with Moses, which Onkelos translated, “and it was spoken!”
But the reason for Onkelos’ translating here, [“Let not aught be spoken to us from before G-d”], is …

ויאמרו אל משה, after they had heard the Ten Commandments.

דבר אתה עמנו, if the Torah had not reported this we would have thought that the people had heard all of the commandments directly from G’d’s mouth.