One of Agrippa's Three Angelic Scripts

Celestial writing appears in the third book of Heinrich Cornelius Agrippa's Three Books of Occult Philosophy, published in 1533, alongside two companion scripts, Malachim and Passing the River, all three presented together as forms of angelic or celestial writing suited to magical and talismanic inscription. Unlike Passing the River, which ciphers Hebrew specifically, Celestial ciphers whichever language a practitioner is writing, standing one for one for the letters of the ordinary Latin alphabet used to write that language, which is why it functions as a disguise for ordinary text rather than as a language with its own independent grammar.

Agrippa gives no earlier source for Celestial writing, and unlike Theban's claimed attribution to Honorius, he does not attach it to a named older authority at all, presenting all three of his angelic scripts simply as forms of writing associated with the celestial and angelic realms his broader occult philosophy describes; this makes Celestial, structurally, a sixteenth century compilation without even the thin, unverifiable claim of deeper antiquity Theban carries through Trithemius.