竹内文書(たけうちもんじょ、たけのうちもんじょ、磯原文書、天津教文書
古代の文書
神代文字で記された文書と、それを武烈天皇の勅命により武内宿禰の孫の平群真鳥が漢字とカタカナ交じり文に訳したとする写本群と、文字の刻まれた石、鉄剣など、一連の総称
天津教の聖典
https://ja.wikipedia.org/wiki/%E7%AB%B9%E5%86%85%E6%96%87%E6%9B%B8
Takeuchi Monjo
Takeuchi monjo (or Takenouchi monjo; also called Isohara monjo or Amatsukyo monjo) is the name for a number of documents written in ancient Japanese characters and include their translations in the form of manuscripts written in a mixture of kanji characters and katakana prepared by HEGURI no Matori, the grandson of TAKENOUCHI no Sukune, under the order of Emperor Buretsu and also inscriptions on stones, iron swords, etc.
https://www.japanese-wiki-corpus.org/literature/Takeuchi%20Monjo.html