Today is Rosh Hodesh Iyyar, the official start to the second month of the Jewish year.* Rosh Hodesh comes up every 29 days or so, always coinciding with the new moon. It's not really a holiday; more like a half-holiday, and the only real observance is a few liturgical additions to daily services.
One of those additions is the recitation of Psalm 104. Every day of the week has its own psalm, but Rosh Hodesh joins the elite club of Yom Kippur and Hanukkah in possessing its own, dedicated psalm.
And this is a psalm with an agenda: it retells Creation, but shifts the context from the perfect (i.e. completed) verb forms of Genesis to the participle (i.e. ongoing) form. For example:
.מַשְׁקֶה הָרִים, מֵעֲלִיּוֹתָיו; מִפְּרִי מַעֲשֶׂיךָ, תִּשְׂבַּע הָאָרֶץ
מַצְמִיחַ חָצִיר, לַבְּהֵמָה, וְעֵשֶׂב, לַעֲבֹדַת הָאָדָם
.לְהוֹצִיא לֶחֶם, מִן-הָאָרֶץ
From Your lofty abode You water the hills; the earth is sated with the fruit of Your works.
You cause grass to grow for cattle and plants for people to cultivate, enabling them to bring forth bread from the earth. (Psalm 104:12,13)
The message is this: Rosh Hodesh may not be much of a holiday, but on it we remember that God continually creates the world. It's a little bit of Rosh Hashanah, eleven (and sometimes twelve) more times per year.
Hodesh tov! Happy Iyyar!
* Yes, the year 5771 started with Rosh Hashanah last September. But the cycle of Jewish months begins in the spring. Go figure!