Good deed for the day

I am looking for origins of the phrase "good deed for the day", as in "Consider it your good deed for the day" - often used in a mildly sarcastic way. Anyone?

For many decades, in the UK at least, part of the Boy Scout Oath was the obligation to "do a good deed for somebody every day" (that was the wording when my brother was a Scout in London in the 1960s). I understand that the British Scout Oath now just says "to help other people". But it was common knowledge in my youth that every Scout had to do a "good deed for the day", and the phrase was often used as you describe - "Come on, lend me half a crown, make it your good deed for the day". (VSD)