But if they turn away – then We have not sent you, [O Muhammad], over them as a guardian; upon you is only [the duty of] notification (the message). And indeed, when We let man taste mercy from us, he rejoices in it; but if evil afflicts him for what his hands have put forth, then indeed, man is ungrateful.
Meaning:-
Rejoice: feel or show great joy or delight.
Afflict: (of a problem or illness) cause pain or suffering to; affect or trouble.