So we have two “Hallel”s: the one we say on holidays, and the one we say everyday. Saying the holiday one every day is problematic, because the תקנה was to say it to celebrate miracles, and miracles don’t happen every day, at least open miracles, נסים גלויים. An important article of faith is that everyday life, just being alive, is a miracle that warrants thanking ה׳. To say הלל everyday is to imply that ה׳ does not do נסים נסתרים, that the universe works independently of ה׳ and ה׳ just intervenes once in a while. And that is מְחָרֵף וּמְגַדֵּף.
And that is the message of אשרי, that introduces פסוקי דזמרא: פותח את ידך; ומשביע לכל חי רצון. And רבי יוסי wanted to be one of חלקי מגומרי הלל בכל יום, who not only said (presumably meaning, with כוונה and not just mumbling the words) the opening chapter, but said the whole thing through the end:
כל הנשמה is ambiguous: we usually translate it as “every soul” but it also means “the whole soul”.
What we call פסוקי דזמרא is תהילים פרקים קמה-קנ. Almost 10 years ago, I started this shiur with a discussion of “אשרי”—תהילים פרק קמה. It starts as a sort of dialog between David—with verses in the first person singular, addressing ה׳ in the second person (ארוממך אלוקי המלך), and previous generations (דור לדור)—with verses addressing ה׳ in the third person (חנון ורחום ה׳), about how to praise ה׳. David wants to praise ה׳: בכל יום אברכך, but realizes that it is impossible: לגדלתו אין חקר, there is no way to describe ה׳‘s greatness. So he needs to look at how previous generations prayed: דור לדור ישבח מעשיך. They praised ה׳’s actions, His manifestation in the world.
And the essence of that תהילה, the climax of אשרי, is פותח את ידך; ומשביע לכל חי רצון.
The Maharal (in his discussion of the סדר) says that the משביע לכל חי, what he calls “פרנסה” is a greater miracle than all the נסים גלויים of יציאת מצרים:
And that’s what our הלל בכל יום is all about. But אשרי doesn’t end there; there is a series of praises of ה׳. They seem to have little to do with one another or with the overall theme of the perek, going from ה׳'s justice (צדיק ה׳) to His desire for prayer (קרוב ה׳ לכל קראיו) to His helping those who fear Him (רצון יראיו) to the destruction of the wicked (כל הרשעים ישמיד). Rabbi Avi Baumol, in The Poetry of Prayer has a striking insight: these pesukim serve as an introduction to the perakim that follow, the ones we say as part of פסוקי דזמרה:
צדיק ה׳ בכל דרכיו; וחסיד בכל מעשיו corresponds to עשה משפט לעשוקים נתן לחם לרעבים; ה׳ מתיר אסורים (תהילים קמו).
קרוב ה׳ לכל קראיו corresponds to רוצה ה׳ את יראיו את המיחלים לחסדו (תהילים קמז).
רצון יראיו יעשה corresponds to וירם קרן לעמו תהלה לכל חסידיו (תהילים קמח).
כל הרשעים ישמיד corresponds to לעשות נקמה בגוים; תוכחות בלאמים (תהילים קמט).
ויברך כל בשר שם קדשו corresponds to כל הנשמה תהלל י־ה (תהילים קנ).
משביע לכל חי רצון isn’t so simple. There is a lot to be said about the universe of the סדור הטבעיי and how it manifests ה׳'s greatness, and why that warrants a הללויה: a public declaration of praise.
We say these perakim every day as part of our תפילות, both as a way of giving ourselves permission to pray (as Rav Soloveitchik, above) but also as a way to prepare ourselves for תפילה. That’s part of what פסוקי דזמרא means:
In order to pray, to ask ה׳ for our needs, we have to walk a very delicate line. We normally live our lives assuming the universe just works, without necessarily feeling the Divine Presence controlling everything, but תפילה means we acknowledge ה׳'s השגחה פרטית. However, being a נודניק כזה to ask הצרכים הפעוטים והקטנטנים הפרטיים שלנו, turns our תפילה into theurgy, magical incantations to control G-d. פסוקי דזמרא is meant to prune away those thoughts.