29. The question apparently is being asked of the Prophet (peace be upon him), but its real audience are the people, who were crossing all limits in their opposition to him. They are being asked: Is Our Messenger asking you for a reward which makes you feel so upset. You know that he is absolutely selfless in his invitation and is exerting himself only for your own benefit and well-being. If you do not want to believe in what he says, you may not, but why are you feeling so enraged at his this invitation to you. (For further explanation, see (E.N. 31 of Surah At-Toor).