According to Hayashiya, the Neiwai liu boluomi jing 内外六波羅蜜經 is listed in Sengyou's recompilation of Dao'an's catalogue of anonymous scriptures 新集安公失譯經録, and was also extant at the time of Sengyou 僧祐. However, Fajing’s Zhongjing mulu includes this text in a group of unseen texts, so it was lost by the time of Fajing. Yancong’s Zhongjing mulu, Jingtai 靜泰錄 and DTNDL 内典錄 also listed this text with the title only, as a 別生經. On the other hand, LDSBJ 三寶記 classifies the Nei li boluomi jing 内六波羅蜜經, a title which clearly refers to the Neiwai liu boluomi jing 内外六波羅蜜經, as a translation by Yan Fotiao 巖佛調, without giving any reasons. No previous catalogues had made such a claim. Further, Hayashiya points out that all texts that Fei Changfang 費長房 attributed to Yan Fotiao were in fact not by Yan Fotiao, with the sole exception of the Shi hui jing 十慧經 (Hayashiya refers to his own work, 巖佛調譯經の研究 [Iseki: 詳細不明], for further explanations). Thus, Fei Changfang's claim that the Neiwai liu boluomi jing 内外六波羅蜜經 was translated by Yan Fotiao is baseless.
By the time of KYL 開元錄, a text entitled Pusa nie xi liu boluomi jing 菩薩内習六波羅蜜經 is noted, and was listed as Yan Fotiao's translation in the KYL. This text is extant today, as the Pusa nei xi liu boluomi jing 菩薩内習六波羅蜜經 T778. Hayashiya claims that the vocabulary and tone of this text shows clearly that it was composed in or around the W. Jin 西晋 period, and cannot have been a translation by Yan Fotiao, who was active in the Latter Han 後漢 period. Hayashiya maintains that KYL classified this Pusa nie xi liu boluomi jing as translated by Yan Fotiao on the simple assumption that it was the same text referred to with by the title Nei liu boluomi jing 内六波羅蜜經, and then following LDSBJ’s ascription.
It remains undetermined whether T778, composed in the W. Jin 西晋 period, is the same text as the Nei liu boluomi jing. Nonetheless, since the Nei liu boluomi jing is listed in Dao’an’s list, it must be classified as an anonymous scripture of the W. Jin 西晋 period or earlier.