He will give the Devil his due
What's the meaning of the phrase 'He will give the Devil his due'?
Literally, pay the devil what you owe him. Used figuratively to mean 'give back what you owe', either money or favours.
What's the origin of the phrase 'He will give the Devil his due'?
From Shakespeare's Henry V Part 1, 1597:
ORLÉANS: And I will take up that with "Give the devil his due."
The expression is referred to in the play as a proverb and so it is likely that Shakespeare was repeating it rather than coining it.
See also: the List of Proverbs.