It seems to correspond to the quoted part of Waobu's johyobun (memorial to the Emperor) which was collected in "Sojo" (Sung Shu) Wakokuden (To the east, Emishi's fifty-five provinces were conquered, and to the west, Shui's sixty-six provinces were conquered).
『宋書』倭国伝に引く倭王武の上表文にみえる「」（東は毛人を征すること五十五国、西は衆夷を服すること六十六国）の表現に対応するかのごとくである。