PREPOSITIONS. Of == "as regards"Of is hence applied not merely to the agent and the instrument, but to any influencing circumstance, in the sense of "as regards," "what comes from."
“Roses are fast flowers of their smells.” B. E. 188. “A valiant man of his hands.” N. P. 614. “But of his cheere did seem too solemn-sad.” SPEN. F. Q. i. 1. Under this head perhaps come:
Which is as thin of substance as the air.
“Niggard of question; but of our demands
Most free in his reply.
“Of his own body he was ill, and gave
The clergy ill example.
i.e. "as regards a fool," "in the matter of folly." This may almost be called a locative case, and may illustrate the Latin idiom "versus animi." It is common in E. E. We still say, in accordance with this idiom, "swift of foot," "ready of wit," &c.
“That did but show thee, of a fool, inconstant
And damnable ungrateful.