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.
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 other phrases and sayings from Shakespeare.