Néhémie 13:24 Halakha : Mishneh Torah, Prayer and the Priestly Blessing

When the people of Israel went into exile in the days of the wicked Nebucednezzar, they mingled with the Persians, Greeks and other nations. In those foreign countries, children were born to them, whose language was confused. Everyone's speech was a mixture of many tongues. No one was able, when he spoke, to express his thoughts adequately in any one language, otherwise than incoherently, as it is said, "And their children spoke half in the speech of Ashdod and they could not speak in the Jews' language, but according to the language of each people" (Nehemiah 13:24). Consequently, when anyone of them prayed in Hebrew, he was unable adequately to express his needs or recount the praises of God, without mixing Hebrew with other languages. When Ezra and his Council realized this condition, they ordained the Eighteen Benedictions in their present order. The first three blessings consist of praises of God and the last three, of thanksgiving to Him. The intermediate benedictions are petitions for the things which may stand as categories of all the desires of the individual and the needs of the community. The object aimed at was that these prayers should be in an orderly form in everyone's mouth, that all should learn them, and thus the prayer of those who were not expert in speech would be as perfect as that of those who had command of a chaste style. For the same reason, they arranged [in a fixed form] all the blessings and prayers for all Jews so that the substance of every blessing should be familiar and current in the mouth of one who is not expert in speech.