Passing the River Tav is drawn as a glyph-form for the Hebrew letter Tav in the Transitus Fluvii, or Passing the River, one of three magical scripts Heinrich Cornelius Agrippa published in 1533, its name recalling a symbolic crossing of the Euphrates, rather than a script with independent letter meanings of its own; Tav'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, Tav 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 Transitus Fluvii alongside Celestial and Malachim 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; the name, recalling the crossing of the Euphrates, is generally read as a reference to the exodus of Abraham's household out of Mesopotamia, a symbolic passage from an older world into the one Hebrew tradition claims for itself. A separate and much later system, the Hermetic Order of the Golden Dawn, mapped Tav 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.