وَمَا أَسْأَلُكُمْ عَلَيْهِ مِنْ أَجْرٍ ۖ إِنْ أَجْرِيَ إِلَّا عَلَىٰ رَبِّ الْعَالَمِينَ (109)
(26:109) I do not ask of you any reward for this duty, for my reward is with the Lord of the worlds; *79
*79) This is the second of the two arguments of Prophet Noah about the truth of his message, the first being that they had known him as a trustworthy man during his earlier life, which he had lived among them. This second argument unplies this: "I do not have any selfish motive or personal interest in conveying the message which I am propagating day and night in spite of all sorts of opposition and antagonism from you. At least you should understand this that 1 am sincere in my invitation, and am presenting honestly only that which I believe to be the truth and in following which I see the true success and well-being of humanity at large. I have no personal motive in this that I should fabricate falsehood to fool the people. "
These two arguments are among the most important arguments which the Qur'an has advanced repeatedly as proofs of the truthfulness of the Prophets, and which it presents as criterion for judging Prophethood. A man who before Prophethood has lived a life in a society and has always been found to be honest, truthful and righteous, cannot be doubted even by a prejudiced person that he would suddenly start fabricating falsehood in the name of Allah and making people believe that he has been appointed a Prophet by Him, whereas he has been not. More important than that: such a lie cannot be fabricated with a good intention unless somebody has a selfish motive attachedto this kind of fraud. And even whena person indulges in this sort of fraud, he cannot hide it completely from the people. The foul means and devices adopted by him to promote his "business" become known and aII the various selfish interests and gains become all too apparent. Contrary to this, the personal life of a Prophet is full of moral excellencies: it has no trace of the employment of foul means and devices. Not to speak of any personal interest, he expends whatever he has for the cause of a mission which to aII appearances is fruitless. No person who possesses any common sense and also has a sense of justice, can ever imagine that a sensible man who was leading a perfectly peaceful life, would come out all of a sudden with a false claim, when such a false claim dces not do him any good, but on the contrary, demands alI his money, time and energy and earns him nothing in return but the antagonism and hostility of the whole world. Sacrifice of personal interests is the foremost proof of a man's sincerity; therefore, doubting the intentions and sincerity of a person who has been sacrificing his personal interests for years and years can only be the pastime of the one who himself is selfish and insincere. 'Please also see E.N. 70 of AI-Mu'minun above.