What I have written stays written is literally “what I have written I have written” (so most translations). The notice was the equivalent of a legal decision, and it could not be altered. What I have written stays written may be rendered “what I have written will remain just that way” or “… will remain just as I have written it.” However, if wrote in verse 19 has been translated as a causative, a causative expression must be employed at this point, for example, “What I have caused to be written will remain just in that form” or “The notice which I ordered written must not be changed.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on the Gospel of John. (UBS Handbook Series). New York: UBS, 1980. For this and other handbooks for translators see here .