When a sentence baffles me, I can usually see the Latin of it after looking at the translation. Then I play the hard sentence in my mind a few times to make the Latin seem more obvious. But this one has resisted: De Officiis, Book II, xix, p. 240 in the Loeb edition.
Diserti igitur hominis et facile laborantis, quodque in patriis est moribus, multorum causas et non gravate et gratuito defendentis beneficia et patrocinia late patent.
I think the key here may be a secondary meaning of pateo: to become wellknown.
If that is correct, then the sentence means something like this:
The good deeds and legal advocacy of an orator become widely known when he works eagerly to defend many clients willingly and without fee.
