"So if you turn away," meaning: if you turn away from the faith, "then I have not asked you" for any reward for what I am inviting you to of this religion, such that it would lead you to abandon what I am inviting you to.
﴿فَإِن توليتم﴾ أَعْرَضْتُمْ عَنِ الإِيمَانِ ﴿فَمَا سَأَلْتُكُمْ﴾ عَلَى مَا أَدْعُوكُمْ إِلَيْهِ مِنْ هَذَا الدِّينِ أَجْرًا، فَيَحْمِلُكُمْ ذَلِكَ عَلَى تَرْكِ مَا أَدْعُوكُمْ إِلَيْهِ.