[أَمْ تَسْأَلُهُمْ خَرْجاً]

(Or is it that you ask them for some Kharj) Al-Hasan said, "A reward.'' Qatadah said, "Some payment.''

[فَخَرَاجُ رَبِّكَ خَيْرٌ]

(But the recompense of your Lord is better,) means, you are not asking for any wages or payment or anything for calling them to right guidance, rather you are hoping for a great reward from Allah, as He says:

[قُلْ مَا سَأَلْتُكُم مِّن أَجْرٍ فَهُوَ لَكُمْ إِنْ أَجْرِىَ إِلاَّ عَلَى اللَّهِ]

(Say: "Whatever wage I might have asked of you is yours. My wage is from Allah only.'') [34:47]

[قُلْ مَآ أَسْـَلُكُمْ عَلَيْهِ مِنْ أَجْرٍ وَمَآ أَنَآ مِنَ الْمُتَكَلِّفِينَ ]

(Say: "No wage do I ask of you for this, nor am I one of the pretenders.'') [38:86]

[قُل لاَّ أَسْـَلُكُمْ عَلَيْهِ أَجْراً إِلاَّ الْمَوَدَّةَ فِى الْقُرْبَى]

(Say: "No reward do I ask of you for this except to be kind to me for my kinship with you.'') [42:23]

[وَجَآءَ مِنْ أَقْصَى الْمَدِينَةِ رَجُلٌ يَسْعَى قَالَ يقَوْمِ اتَّبِعُواْ الْمُرْسَلِينَ اتَّبِعُواْ مَن لاَّ يَسْـَلُكُمْ أَجْراً]

(And there came a man running from the farthest part of the town. He said: "O my people! Obey the Messengers. Obey those who ask no wages of you, and who are rightly guided.'') [35:20-21]

[وَإِنَّكَ لَتَدْعُوهُمْ إِلَى صِرَطٍ مُّسْتَقِيمٍ - وَإِنَّ الَّذِينَ لاَ يُؤْمِنُونَ بِالاٌّخِرَةِ عَنِ الصِّرَطِ لَنَـكِبُونَ ]

(And certainly, you call them to the straight path. And verily, those who believe not in the Hereafter are indeed deviating far astray from the path.)