It is obviously beyond the ability of even the greatest contemporary man to memorize all of the details of the Torah in forty days, simultaneously comprehending all of its profundities. Moshe did all of this while he also learned how to observe the mitzvos, including the specifics of the construction of the Mishkan and its appurtenances, which are not written in the Torah. Consequently, we may deduce that the process of study which transpired on the mountain was nothing less than a miraculous feat. Hashem bestowed this wisdom upon Moshe as one would pour wine into a vessel.
The question thus arises: Why were the forty days an integral part of this learning process? This great wisdom could have been miraculously imparted to Moshe in a single moment. We may derive from here that Moshe’s effort was required. Forty days of extreme mental intensity were mandated. Only after this unique endeavor, however, was he rewarded with miraculous success. The ordeal of total mental concentration for forty days and nights, complimented by divine assistance resulted in Moshe’s ability to comprehend the complete Torah. This procedure was specifically intended to serve as a paradigm for the process of future successful study. Effort is always required, no matter how unique the talents of the individual. Hashem rewards effort with success.