Rashi cites the Mechilta that emphasizes the word “these.” Hashem told Moshe to relate specifically what he was told — no more, no less. We can understand insisting that Moshe not change what he was told to say in any form. Why would it be inappropriate for Moshe to speak a little more, if his words would result in his teaching more Torah. Was there a limit on what Moshe was to teach?
Horav Avner Okliensky, zl, comments that man’s purpose in life is to garner all of his resources and abilities in order to maximize his potential for the specific purpose of Torah study and mitzvah performance. If Hashem has granted an individual extraordinary acumen, he must employ it in the pursuit of Torah knowledge. If Moshe were to go beyond the parameters of Divine mandate, he might be teaching Torah to Bnei Yisrael, probably making it easier for them to grasp. He would be, however, depriving each individual from attaining his own potential. They would no longer toil to understand Torah. It would not be his own comprehension of Torah — it would be Moshe’s! This is not what Hashem expects of a Jew.
