The expression “to feather one’s nest” means to provide for one’s comfort; especially, for comfort in later life by massing wealth.
The import is to the practice of many birds which, after building their nests, pluck down from their breasts to provide a soft lining that will be comfortable during the long hours of setting upon the eggs.
The oldest English literary occurrence is in 1553, but a more typical example is that used in 1590 by the young poet, Robert Greene, “She sees thou hest fethred thy nest, and bast crowns in thy purse.”
