One of the important introductory sections to the morning prayer service is Hodu, a chapter taken from the Book of Dibreh Hayamim I (16:8-36). There is a parallel chapter in Tehillim (105:1-8), with some slight differences, but the chapter we incorporate into our daily prayer service is the one in Dibreh Hayamim. The Arizal (Rav Yishak Luria, Safed, 1534-1572) taught that the recitation of Hodu plays a crucial role in assuring that our prayers reach the heavens. Over the course of the prayer service, the Arizal explained, we gradually ascend higher from one realm to the next, and the recitation of Hodu is the way we rise from the realm of "Asiya" to the realm of "Yesira." We then continually ascend until we reach the highest realm – "Asilut" – where we are standing right before Hashem. Each time we rise from one level to the next, the Kelipot (negative spiritual forces) threaten to sabotage our process of ascent, thereby preventing our Tefilot from reaching their destination. The recitation of Hodu helps protect us from the Kelipot as we make our way upwards. As such, it is critically important for a person to arrive at the synagogue on time so he can recite Hodu at the beginning of the prayer service. The Arizal said that if a person arrives late, such that he must skip Hodu, then even if he recites it later, after Shaharit, this will be ineffective, and will resemble putting on one's undergarments over his suit. When a person gets dressed, he must follow the proper sequence, putting on each layer at the appropriate stage. The same is true of the Tefila. The prayer book is called a "Siddur" because it is arranged according to the "Seder" – sequence – that we must follow to help ensure that our prayers will be effective and will achieve the desired results. Although a number of ancient texts of the Siddur – such as the Siddur of Rav Amram Gaon, and the Rambam's text – do not include Hodu, our custom is to recite Hodu in accordance with the Arizal's teachings. What is the particular significance of this chapter? Why must we recite these verses before we begin the prayer service? The Rokeah (Rav Eliezer of Worms, Germany, c. 1176-1238) explains that the incorporation of this chapter in the Siddur is rooted in the story told in the Book of Shemuel I about the Aron (ark), which Beneh Yisrael took out to war when they fought the Pelishtim. The Pelishtim defeated Beneh Yisrael, and captured the Aron. Hashem responded by punishing the Pelishtim, and they soon realized that they needed to return the ark to Beneh Yisrael. They placed it on a wagon which they attached to cows, and they then sent the cows toward the nearest Israelite town. The verse says that the cows sang as they traveled, and the Rokeah writes that the song they sang was Hodu. In commemoration of this miracle, King David had this song sung before the Aron. According to some, it was sung each day. The first verse contains seven words ("Hodu L'Hashem Kir'u Bi'shmo, Hodi'u Ba'amim Alilotav"), alluding to the seven months the Aron spent in the land of Pelishtim, bringing suffering upon them. The term "Hodu" means "give thanks," and it denotes specifically the feeling that one has received more than he deserves. After Leah gave birth to Yehuda, her fourth son, she exclaimed, "Ha'pa'am Odeh Et Hashem" ("This time, I shall give thanks to G-d" – Bereshit 29:35), and the commentators explain that she felt especially grateful at that point because she was now blessed with more children than Yaakob's other wives. She knew that Yaakob was destined to beget 12 sons, and thus the birth of her fourth son meant that she had the privilege of producing more children than the other wives. The term "Hodu," then, refers to the recognition that we have been given more than we rightfully deserve. King David exclaimed, "Hodu" because he genuinely felt that he had been blessed with so much more than he deserved. He was a descendant of Rut – a convert from the nation of Moab – and there was considerable controversy about whether her marriage to Boaz was halachically valid. And yet, despite this controversy, David was not only accepted, but also appointed king over the people. He lived with profound gratitude over this privilege, and so he exclaimed, "Hodu." When we recite Hodu, then, it is proper to pause for a moment and reflect upon all the blessings in our lives, and how we have been mercifully given so much more than we can honestly claim we deserve. Some sources say that the chapter of Hodu was sung during the offering of the daily Tamid sacrifice during the time of King David. Appropriately, then, immediately after our recitation of the Korbanot section, commemorating the daily sacrifices in the Bet Ha'mikdash, we recite Hodu. These verses include ten different expressions of praise – "Hodu," "Kir'u," "Hodi'u," "Shiru," "Zameru," "Sihu," "Hit'halelu," "Dirshu," "Bakshu," and "Zichru." Some explain that these expressions correspond to the ten plagues that G-d brought upon Egypt. Others suggest that in the morning, with the renewal of nature, we allude to the ten Ma'amarot – pronouncements – with which Hashem created the world. Moreover, these verses make mention of the three patriarchs, all of whom are associated with the number 10. Abraham was given ten tests; Yishak pronounced ten different expressions when blessing his son; and Yaakob pledged to donate one-tenth of his earnings. Accordingly, these verses – which mention the patriarchs in order to invoke their great merit – contains specifically ten expressions of praise.