Preliminary Blessings and Psalms
With introductory blessings and psalms, the creators of the Jewish prayer service created a model that allowed for spiritual preparation prior to the main section of the morning service.
Rabbi Kohn describes the preparatory materials that precede the main morning service. These materials include blessings, readings from the Torah and Rabbinic literature, and extended selections from the Psalms.
The Rabbis of the Talmud state: "One should not stand up to pray unless it is with a sense of respectful awe. The early pious ones used to wait an hour and then pray in order to better focus their hearts on God" (Mishnah Berakhot 5:1). Given the fact that the Rabbis established a fixed structure of obligatory prayers, they recognized and encouraged worshippers to take the time to develop and enter into an appropriately reflective and meditative state of mind. The Rabbis even warned, "Do not make your prayers perfunctory, rather, they should be true entreaties before the Holy One, blessed be God" (Pirkei Avot 2:13). To ensure that people would recite important prayers like the Shema and its blessings and the Amidah in a meditative mood, they created an introductory liturgical unit to the morning worship service called Birkhot HaShahar, or "Blessings of the Morning."
Originally recited by individuals in their home as they awoke, washed, and dressed for the day, these blessings, such as thanking God for giving sight to the blind (once recited before one opened his or her eyes in the morning), raising the downtrodden (recited before standing up from bed), and clothing the naked (recited before getting dressed), were transferred to the synagogue and included in the siddur. This section also included blessings after using the bathroom, a prayer thanking God for the creation of our souls, and selections of biblical and rabbinic texts to fulfill the daily mandatory requirement to study Torah every day.
A second, larger, more spiritually reflective set of preliminary readings following the Birkhot HaShahar section is called Pesukei D'Zimra (verses of song). These verses of song include a lengthy selection of psalms and passages from the Hebrew Bible chosen precisely to increase the kavvanah, or spiritual focus, of the one who is praying. These readings are sandwiched between an opening and closing blessing separated by the numerous exerpts from the Bible. The opening blessing is named after its first line, Barukh Sh'amar, or "Blessed is the One who spoke." Barukh Sh'amar consists of 11 different attributes of God, such as Creator, Redeemer, and Rewarder, beginning with the word barukh, blessed. The opening blessing of this section states, "Blessed are you, Adonai our God, King, extolled with songs of praise."
Following Barukh Sh'amar are a couple of compilations of verses, selected mostly from the Psalms, but including some passages from Chronicles and Proverbs, called Hodu L'Adonai kir'u vi'shmo (Give thanks to the Lord, call upon His name) and Yehi Khevod. In between these two passages, Psalm 100, Mizmor L'Todah (a psalm of thanksgiving) is recited on weekdays. "Worship the Lord with joy" the psalm exults, "come before the Lord with songs of gladness!"