Barukh she'amar
Barukh she'amar (בָּרוּךְ שֶׁאָמַר, baruch sheamar, or other variant English spellings), is the opening blessing to pesukei dezimra.
The prominent version of Barukh sheamar contains 87 words. This is the gematria of the Hebrew word paz (פז) meaning "refined gold.". An alternative text is printed in some Sephardic prayer books, often alongside the traditional version.
Purpose
Barukh she'amar acts as a transition in the prayer service. In the Syrian tradition, the common melody for the prayer is derived from that of Hatikvah.
Origin
Initially, Saadya Gaon instituted the recitation of barukh she'amar for Shabbat, but in France, it became a custom to recite this prayer daily.
In the Sephardic and Oriental liturgy, the custom is to recite all the additional psalms of Shabbat prior to Barukh sheamar on Shabbat.
Aspects of God
There are seven aspects of God mentioned in Barukh she'amar. These are:
God spoke and the world came to be.
God speaks, does, decrees, and fulfills.
God is merciful.