"if anyone takes away from the words of the book of this prophecy, God will take away his share in the tree of life and in the holy city, which are described in this book." (Rev. 22:19; ESV)In the case of Christian authors and scribes, God's judgement was often given to those who would dare mutilate a text. Here are a some examples;
(ca. 180 CE) Irenaeus of Lugdunum, Gaul (modern day Lyons, France), in his "Against Heresies" discussed a variant reading for the 'mark of the beast' of Revelation in some manuscripts of his day (see previous post here). After noting that some inferior copies of Revelation read '616' instead of '666' alluding to the curse found in Revelation 22:19 he wrote,
"there shall be no light punishment [inflicted] upon him who either adds or subtracts anything from the Scripture,under that such a person must necessarily fall." (Hear. 5.30.1; ANF 1:559)(ca. 390 CE) Rufinus of Aquileia translated Origen's De principiis from Greek into Latin. In the preface to his translation he affixed a warning,
"[V]erily, in the presence of God the Father, and of the Son, and of the Holy Spirit, I adjure and beseech every one, who may either transcribe or read these books, by his belief in the kingdom to come, by the mystery of the resurrection from the dead, and by that everlasting fire prepared for the devil and his angels, that, as he would not possess for an eternal inheritance that place where there is weeping and gnashing of teeth, and where their fire is not quenched and their worm dieth not, he add nothing to Scripture, and take nothing away from it, and make no insertion or alteration, but that he compare his transcript with the copies from which he made it, and make the emendations and distinctions according to the letter, and not have his manuscript incorrect or indistinct, lest the difficulty of ascertaining the sense, from the indistinctness of the copy, should cause greater difficulties to the readers" (De prin. praef.;ANF 4:238)As Gamble noted in his "Books and Readers," Christians were not the only ancient writers and copyists to invoke a divine sanction against the corruption of a text. Artemidorus, writing about the same time as Irenaeus affixed at the end of his work on the interpretation of dreams.
"I ask those who read my books not to add or remove anything from the present contents. For any person who is able to add points to my work would more easily write a work of his own. And if certain things that I have written in these books seem superfluous, the reader should use only those things that please him without discarding the rest of the books. For he should realize that it was out of obedience to Apollo, the overseer god and guardian of all things in addition to being my own native god, that I undertook this treatise. Apollo has encouraged me in the past, and now especially, when I have made your acquaintance, he clearly presides over my work, and has all but commanded me to compose this work." (Oneir. 2.70; Gamble, "Books and Readers," 125)In the case of Artemidorus, it is the god Apollo who entreated him to compose the work and it is Apollo who watches over his work so that it may not be corrupted through copying.
For further reading on the use of divine sanctions against the alteration of texts, see Michael J. Kruger, "Early Christian Attitudes toward the Reproduction of Texts," pages 63-80 in
"The Early Text of the New Testament(Edited by C. R. Hill and Michael J. Kruger. Oxford: Oxford University Press, 2012).
Harry Y. Gamble, "Books and Readers in the Early Church: A History of Early Christian Texts" (New Haven: Yale University Press, 1995).