Arab translation of Psalter, completed in Al-Andalus by Hafs b. Albar Al-Kuti in 889, has repeatedly become an object of foreign researchers' study. As a result, there was published a number of manuscripts with detailed textological comments. Contemporary publications include the abstracts of this Psalter, as well as its full text, considering Psalter primarily from cultural and historical points of view, whereas this article contains an attempt of this text's analysis within the framework of socio-linguistic approach. The authors answer to the following questions: why was the first poetic translation made on the territory of modern Spain, why did the author decide to translate it into Arabic, while the majority of church figures actively opted for preservation of Latin as the language of The Holy Scripture, and finally, why there was specifically chosen the text of Psalter? In his prologue to Psalter - Urjuz the author defends Arabic by defining the Latin language as the foreign one. In addition, he explains