Conversation is but carving;
Carve for all, yourself is starving:
Give no more to every Guest,
Than he’s able to digest;
Give him always of the Prime;
And but little at a Time.
Carve to all but just enough:
Let them neither starve nor stuff:
And, that you may have your Due,
Let your Neighbours carve for you.

Jonathan Swift (1667-1745) English writer and churchman

“An Epistle to a Lady Who Desired the Author to Write Some Verses Upon Her in the Heroic Style,” ll. 123-132 (1732)
    (Source)

Often rendered with the first line ending in an exclamation point, and the second line missing.