New Time

Why is kiddush hachodesh the first mitzvah given to Klal Yisroel?  The Gemorah says that there are ten utterances used by G-d in creation. The Gemorah asks but it only says ויאמר 9 times in the creation story.  It answers בראשית also refers to a creation (Rosh Hashana 32a.)  What was created with the word בראשית?  The Siddur Eshai Yisroel in the Siach Yitzchak on ברוך עושה בראשית in ברוך שאמר it says that time was created with the word בראשית.  He says that is the meaning of עושה בראשית; the One who created time itself.
The events of the exodus were a second form of creation.  There was the creation of the world which runs based upon the rules and principles of טבע.  This creation is celebrated on Rosh Hashana, in Tishray, the beginning of the world.  That was the first creation.  In the Exodus a second form of creation emerged.  This creation is the creation dominated by the rules of Torah.  In this creation, the world is run with miracles and the rules of nature are broken for the need of Torah.  This creation is celebrated in Nissan, through the mitzvah of kiddush hachodesh.  In this creation Klal Yisroel is given control over the month to rule it based upon the rules of the second creation, based upon the rules of Torah.  We aren't celebrating the existence of the moon, rather our control over it. (As in the Yerushalmi Ketuvot 4a about בתוליה חוזרין.)  [Based upon Rav Yitzchak Eizek Chaver and Mizmor L'Dovid.]