وَتَجْعَلُونَ رِزْقَكُمْ أَنَّكُمْ تُكَذِّبُونَ
Wa taj'aloona rizqakum annakum tukazziboon
And how, in return for the livelihood you are given, can you deny it?
and make your denial the return for what sustains you?
The word rendered here as sustenance is rizq, and the sentence puts it where a payment would go, so what a person gives back for being fed turns out to be the denial itself. Early commentators glossed the phrase as your thanks, and many tied it to the oath seven verses earlier by the positions of the stars, since rain was credited in Arabia to particular stars as they set. The charge just before is lighter, that the message is handled casually; this one makes it a debt.