They consider it a favor to you that they have accepted Islam. Say, "Do not consider your Islam a favor to me. Rather, Allah has conferred favor upon you that He has guided you to the faith, if you should be truthful."
English Transliteration
Yamunnoona AAalayka an aslamoo qul la tamunnoo AAalayya islamakum bali Allahu yamunnu AAalaykum an hadakum lileemani in kuntum sadiqeena
Tafsir of Verse 17
They count it as a favour to thee that they have surrendered! Say: 'Do not count your surrendering as a favour to me; nay, but rather God confers a favour upon you, in that He has guided you to belief, if it be that you are truthful.
They impress on thee as a favour that they have embraced Islam. Say, "Count not your Islam as a favour upon me: Nay, Allah has conferred a favour upon you that He has guided you to the faith, if ye be true and sincere.