A carol-like rhyme from the days when children went door to door at Christmas asking for pennies for an old man's hat. Its sliding scale, a penny, a ha'penny, or just a blessing, teaches generosity without ever sounding like a lesson.
From Mother Goose / Nursery Rhymes (traditional). See the whole collection.
Christmas is coming, the geese are getting fat,
Please to put a penny in an old man's hat;
If you haven't got a penny a ha'penny will do,
If you haven't got a ha'penny, God bless you.
Public domain. Text from The Real Mother Goose (Blanche Fisher Wright, 1916), via Project Gutenberg. View the source edition