We all have a picture in our mind of what happened at Har Sinai - Moshe Rabeinu standing at the top of the mountain, receiving the Luchos, while Hashem speaks to Am Yisrael - that's what we've been taught since kindergarten.
However, when looking in the Psukim, this is not what's described!
And more than that, Hashem seems to keep on telling Moshe to go up onto the mountain, and then down - again and again - what's this all about?
Where was Moshe during Mamad Har Sinai?
How should you really picture what was going over there?