E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Spear of Ithuriel (The),
the slightest touch of which exposed deceit. Thus when Ithuriel touched with his spear Satan squatting like a toad close to the ear of Eve, the toad instantly resumed the form of Satan. (Milton: Paradise Lost, bk. iv. 810814.)
The acute pen of Lord Halles, which, like Ithuriels spear, conjured so many shadows from Scottish history, dismissed among the rest those of Banquo and Fleance.Sir W. Scott.