a bribe
Examples
I have often noticed that a bribe has that effect - it changes a relation. The man who offers a bribe gives away a little of his own importance; the bribe once accepted, he becomes the inferior, like a man who has paid for a woman.
Marriage is a bribe to make the housekeeper think she's a householder.
A man to whom you do a favor will not understand if you say nothing, make no noise, just walk away. You may cause more trouble by refusing a bribe than by accepting it.
Nevertheless, this one fact should be apparent: turning the other cheek is a bribe. It is a valid form of action for only so long as the Christian is impotent politically or militarily.
The promise of Christ to reward those who will believe is a bribe.
Heaven was inspired by the first judge to take a bribe.