Dating back the period between XI-XV centuries, more precisely, before the formation of national languages, numerous relicts survived our era in the Arabic script. According to the unanimous opinion of turkologists, all these historical monuments were written in the Karluk-Uyghur, Oghuz, and Kipchak languages. However, Turkology has not determined yet the contribution of each language to a particular monument. Therefore, most monuments are only allegedly defined. Only statistical analysis can answer the question of how much the Oghuz, Kipchak and Karluk-Uyghur languages relate to each monument. Thus, the analysis is one of the most urgent issues. For the successful research, the importance of identifying similarities and differences in several copies of each monument is not less important. To compare three manuscripts of the "Hıbat-ul-Haqaıiq" monument (The Gift of the Truth), to find the differences and to restore the author's originality as much as possible. The article proposes several ways to restore the author's original: a method of statistical analysis, methods of historical comparison, a method of component analysis. It was determined that the monument "Hıbat-ul-Haqaıiq" was written in the Turkic-Kipchak language, and not in the Karluk-Uygur language, as turkologists had previously claimed. If to apply our approach to analyze other monuments' manuscripts, great results are unfailingly achievable.