The Men of the Great Assembly instituted the prayers and the blessings (Berakhot 33a). They set the wording of the Shemoneh Esrei and formulated all the berakhot, including those recited before and after the recitation of Shema (Birkhot Keri’at Shema) and Birkhot Ha-nehenin (blessings recited upon deriving pleasure from something). They also instituted the recitation of the three daily prayers, Shaĥarit, Minĥa, and Ma’ariv – Shaĥarit and Minĥa as obligations and Ma’ariv as a voluntary prayer.
The members Ezra the Scribe’s court, established at the beginning of the Second Temple period, are called the Men of the Great Assembly (Anshei Knesset Ha-gedola). This was the greatest beit din ever convened in Jewish history. It was comprised of 120 elders, among them prophets and sages such as, Ĥagai, Zechariah, Malachi, Daniel, Ĥanania, Mishael, Azaria, Neĥemia b. Ĥakhalia, Mordechai Balshan, and Zerubavel, as well as many other sages, the last one being Shimon Ha-tzaddik (Rambam, Introduction to Mishneh Torah).
During the time of the First Temple, the Jewish people attained superior spiritual accomplishments: the Shekhina dwelled in the Temple and the great scholars of Israel achieved prophecy. Nevertheless, grave sins like idolatry, forbidden sexual relations, and murder proliferated amongst the masses, ultimately causing the Temple’s destruction and the exile of the people of Israel. Therefore, when Israel was able to rebuild the Temple, the Men of the Great Assembly constituted a large beit din, set safeguards for the Torah, made enactments, and formulated and arranged prayers and berakhot. They created a full framework for Jewish life, giving expression to Torah values in an organized and established manner within everyday living, thereby distancing the nation from sin and bringing them closer to serving God.
Of course, even in the First Temple era, Israel prayed to God and thanked Him for all the good and blessing they received. However, those prayers did not have a set formula. Since it had no set formula, righteous and devout people would pray and recite berakhot with great kavana (focus), but the masses would minimally fulfill their duties with shallow prayers. Passionate prayer from the heart in one’s own words is the ideal form of prayer, but in actuality, the routine demands of everyday life wear us out, and without regular fixed prayers, the public gradually drifts away from worshipful prayer and eventually from God. Following the establishment of the prayers and their fixed wording, all of Israel started to pray, and as a result, faith in God intensified. That is what sustained the nation’s devotion that even two thousand years of exile could not extinguish.
Moreover, during the time of the First Temple many people mistakenly regarded the offering of korbanot as idolatrous acts possessing magical powers, able to grant good fortune in matters such as livelihood, health, and the abolishment of evil decrees. The prophets severely condemned this misguided notion and taught that a korban in its essence, is an expression of the people’s desire to get closer to God through total devotion. That is the primary purpose of humanity in this world, as The torah states (Devarim 10:12): “What does God want of you? Only that you revere the Lord your God, follow all His ways, love Him, and serve the Lord your God with all your heart and with all your soul.” When the person who brings the offering does not demonstrate true devotion to God nor the desire to improve, not only is the offering ineffective, but it is repulsive in God’s eyes, as it is written: “‘Why do I need all your sacrifices?’ God asks. ‘I am sated with your burnt offerings of rams and the fat of fed beasts, and I have no desire for the blood of cattle, sheep, and goats. When you appear before Me, who asked you to do this, trampling My courts? Do not bring any more vain meal offerings; incense is offensive to Me…’” (Yeshayahu 1:11-13). By instituting the prayers, the Men of the Great Assembly restored the proper priorities to the worship of God, reminding us that faith, focus, and devotion are primary. These values indeed find their clear expression in the prayers, as R. Elazar said, “Prayer is greater than sacrifices” (Berakhot 32b). By emphasizing our kavana, we pray to God that He rebuild the Temple speedily in our time so that we may express our devotion to Him fully – through both prayer and sacrifice.