What or where or who on this quotation

"Not knowing, I hesitate in replying to any specified degree of accuracy, but if my dramatic articulation is too opaque for your comprehensibility, I shall endeavor to render myself more lucid by eradicating all monosyllabic verbosities."

My 84 year old father taught me this 40 years ago and he knew it as a young man. It was on a card purchased with other bits of doggerel, but this is the only one I know.

Thank you.