I continually see Rosh Chodesh identified as "the first mitzvah in the Torah". I recognize that it is the first mitzvah given to Am Yisrael as a nation. But there are three mitzvot that precede it in the Torah: 1) To be fruitful and multiply; 2) brit milah; and 3) not to eat the sinew of the thigh-vein. So why does rosh chodesh carry the title of "the first mitzvah in the Torah" as opposed to "the first mitzvah given to the Jewish people"? Many thanks and Pesach Kasher v'Sameach. Shavua tov.
 There are many such examples on-line and elsewhere. One example, from the Orthodox Union's Torah Tidbits: "Parshat HaChodesh: Discovering the Meaning of the First Mitzvah according to Rav Kook zt"l With the setting of the sun on Shabbat afternoon in Jerusalem, students of the Mercaz HaRav Yeshiva would gather to hear the words of their master Rabbi Abraham Isaac Kook zt"l...these talks were transcribed...One Shabbat...Rabbi Kook addressed the significance of the Torah's first mitzvah: Sanctifying the new month.."