Is it farther or further?
at first in late Old English predician, a loan word from Church Latin; reborrowed 12c. as preachen, from Old French preechier "to preach, give a sermon" (11c., Modern French précher), from Late Latin praedicare "to proclaim publicly, announce" (in Medieval Latin "to preach"), from Latin prae "before" (see pre-) + dicare "to proclaim, to say" (see diction). Related: Preached; preaching. To preach to the converted is recorded from 1867 (form preach to the choir attested from 1979).