The Torah is enjoining people to prepare for the moment of Revelation when they will receive the Torah. They are to wash their clothes and fix limits around the mountain, so that no human or animal would be able to come closer. We may note the distinction of these two mitzvos - washing clothes and cordoning off the periphery of the mountain. Horav Y.A. Hirshovitz, zl, suggests that these two mitzvos serve not only as preparatory agents for Klal Yisrael's ascent to religious nationhood, they underscore the kedushas ha'Torah, the sanctity of Torah. The remind us how distant we were then from the Torah's ideal.
Every religion is the product of the generation in which it was introduced.
Thus, all religions are subject to the influence of the place, time and culture from which it emerged. Certainly, the people who initiated it as a creed affected the formation of the religious dogma, codes, and form of service. A religion which the people initiated will ostensibly have passed the critique of the people. This applies to all religions - except the one religion that was given by the Almighty to His Chosen People. Judaism is not a figment of human imagination.