|34th||It is good Manners to prefer them to whom we Speak before ourselves especially if they be above us with whom in no Sort we ought to begin.|
What I believe is meant here is that we should, as stated in scripture (Philippians 2:3 NASB -
3 Do nothing from selfishness or empty conceit, but with humility of mind regard one another as more important than yourselves .) Consider others as more important than yourselves. I don't know that at this time George was considering Philippians, but I imagine he had been taught the concept.
The other part of his quote, "especially if they be above us", etc., relates, again, to the era in which George lived. Before the United States became its own nation, we lived under British rule, where people had certain social standing and knew where they stood as compared with those they were associating with. One knew if one was with another who was "above" them in the social heirarchy.