In the third month after the Sons of Israel went forth from the land of Egypt on this day they came to the wilderness of Sinai. (Shemos 19:1)
This verse is unusual because it does not begin with “And,” as is the style of the Torah everywhere (see Bereshis 1:2). Also: the following verse states “And they journeyed from Refidim and they came to the wilderness of Sinai,” which is the regular continuation of the narrative, thus making this first verse (19:1) superfluous except for the date. It is thus obvious that the date is being emphasized in the first verse, and to strengthen the emphasis the word “And” is omitted.
This is as if to say that now is a great new beginning that commences with the Giving of the Torah. Everything that went before, from the creation of the Universe down to this day, was but the preface to this event which was now about to transpire. Just as Bereshis began without “And,” because it was the great beginning, so also does the episode of the Giving of the Torah not begin with an “And” because it was the great Beginning of the era of Torah.
Everything since Creation was the preface to what was now about to transpire
Actually it can be considered not only the Beginning of Torah but the Beginning of the Universe, because everything that had transpired in the world’s history was a preface to the Giving of the Torah at Sinai.
The Torah was not given in the Holy land, but in the Wilderness. Among the many reasons that could be offered, the following are mentioned: