Celestial Kaph is drawn as a glyph-form for the Hebrew letter Kaph in the Alphabetum Coeleste, one of three magical scripts Heinrich Cornelius Agrippa published in 1533, its strokes tipped with small circles in imitation of star charts, rather than a script with independent letter meanings of its own; Kaph's own sound and classification, discussed elsewhere in this atlas, belong to the underlying Hebrew tradition.
As one of the Sefer Yetzirah's seven double letters, Kaph carries both a hard and a soft pronunciation depending on whether it takes a dagesh, and is traditionally assigned, alongside its six sibling double letters, one of the seven classical planets and one of seven paired opposites; which specific planet and pair belong to which of the seven letters is a point on which recensions of the Sefer Yetzirah disagree, and this atlas does not adjudicate between them.
Agrippa printed Celestial alongside Malachim and Passing the River in Book III of his Three Books of Occult Philosophy, Cologne 1533, without citing a source for any of the three, and no earlier witness to any of them survives; historians generally read the scripts as a Christian Kabbalist's own reworking of Hebrew letters into star-chart-like glyphs for use on talismans and amulets, most likely Agrippa's own invention following Johannes Reuchlin's earlier Christian engagement with Hebrew letter mysticism a generation before. A separate and much later system, the Hermetic Order of the Golden Dawn, mapped Kaph onto its own tarot trump and planet along the Kabbalistic Tree of Life, an attribution discussed under the Hebrew letter elsewhere in this atlas and unconnected to this Renaissance glyph in its own right.