The present study attempts to reread and reinterpret the fifteenth line on the southern face of the Bilga Kaghan Inscription. First, it is proposed that the sign group < tImG > in the line can be transcribed as timag(1) 'preparation'. Secondly, the article shows that the sign group following the second etdi starts with the signs < Ig > and not with <*Wg >. The adjacent lacuna is proposed to be reconstructed as ig[idmis], and its continuation as ka[g]an[ina bun]ca. Thirdly, it is pointed out that the predicate of the related sentence ends not with *<...WrtI >, but with <...IrtI >. Here, this defective lexeme is transcribed as <[b]ertI >. Finally, the signs which are inscribed between < bglr:BWDN > and the proposed <[b]IrtI > form are reconstructed and transcribed as [It]I:Y[RTW:] = [et]i : y[aratu:], taking into account the data in the Finnish Atlas and Radloff's retouched copy. The paper is organized as follows. Section 1 is the introduction. Section 2 deals with the major studies on the problematic part of the inscription. In section 3, a new reading is proposed. The lessons drawn from these findings are then summarised in Section 4, the conclusion.