日本古代の文書行政の実態を知る上で極めて重要な史料と位置づけられている正倉院文書には，周知のように実に多種の古代印が押されている。本稿では，その中から，特に東大寺内の組織運営システムと密接にかかわると考えられる「東大寺印」と「造東寺印」を取り上げ，これまで主に個々の文書の接続関係や内容から検討されてきた正倉院文書に，印影の考察から，新たな分析視角を与えることを試みる。正倉院文書中に見られる「東大寺印」は現在三種が確認できるが，そのうち，古代印と認められるものは二種である。また，同じく「造東寺印」も二種を確認したが，古代印と断定できるものは一種のみであった。このことを前提として，「東大寺印」「造東寺印」の変遷と両印の関係を示すと以下のようになる。天平宝字５年末までに鋳造された「東大寺印」は，宝亀２年に他の寺印が官鋳で頒下されるに伴って，改鋳されることとなる。一方「造東寺印」も天平勝宝４年10月から宝亀２年９月の間は少なくとも存在していることが確認される。造東大寺司の作成する文書にはこの両印がいずれも使用されているが，造東大寺司では，寺内に伝達する文書には「造東寺印」を押印し，寺外に伝達する文書には「東大寺印」を押印するという，文書行政上の使い分けを行っていたと考えられる。なお，天平勝宝４年以降，造東大寺司と東大寺三綱は，互いに往復する文書にそれぞれの東大寺内での所属名を冠した印を用いており，造東大寺司と三綱が同居する東大寺はその内部において，少なくとも奈良時代中葉以降は，それぞれの所属の印を用いた文書による組織運営システムを確立しつつあったことが窺われるのである。

The Shōsō-In Documents (正倉院文書), classified as extremely important materials for ascertaining the actual state of the documentary governance of Japan in old times, bear a variety of old seals as already known to the people concerned. This paper discusses, among others, the “Tōdaiji Seal” (東大寺印) and the “Zōtōji Seal” (造東寺印) which are considered to have had a close relationship particularly with the management system of Tōdaiji Temple, trying to give a new perspective over the Shōsō-in Documents, so far studied principally with respect to mutual positional relationship of the contexts of individual documents separated into a plural number of sheets, from the viewpoint of studies on seal marks.Three types of “Tōdaiji Seals” appearing in the Shōsō-in Documents were already identified, and two of the said three are ascertained as old seal marks. Identically, three type of “Zōtōji Seals” were also identified, but only one type was determined as an old time seal. Based on this fact, the changes and mutual relationship of both the “Tōdaiji Seals” and “Zōtōji Seals” can be confirmed as shown below.The Tōdaiji Seal, cast at and before the end of the 5th year of Tempyōhōji (A.D.761), was recast simultaneously with the seal marks of other temples were cast officially and issued in the 2nd year of Hōki (A.D.771). The presence of the Zōtōji Seal during the period from the October of the 4th year of Tempyōshōhō (A.D.751) to September of the 2nd year of Hōki (A.D.771) was confirmed, but it is considered that the office of Zōtōdaiji-shi (造東大寺司) used the Zōtōji Seal in their internal documents while putting the Tōdaiji Seal in the documents issued outside the temple.In addition, after the 4th year of Tempyōshōhō, the officials of Zōtōdaiji-shi and Sangō (三綱) of Tōdaiji Temple used in their mutually exchanged documents the seals bearing their sections to which they belonged. This shows that after the middle of the Nara era, a administrative system using official documents affixed with seals was being established in Tōdaiji Temple including the offices of Zōtōdaiji-shi and Sangō managing household of Tōdaiji Temple.

source:https://www.rekihaku.ac.jp/outline/publication/ronbun/ronbun4/index.html#no79