﴿ يَمُنُّونَ عَلَيْكَ أَنْ أَسْلَمُوا۟ ۖ قُل لَّا تَمُنُّوا۟ عَلَىَّ إِسْلَٰمَكُم ۖ بَلِ ٱللَّهُ يَمُنُّ عَلَيْكُمْ أَنْ هَدَىٰكُمْ لِلْإِيمَٰنِ إِن كُنتُمْ صَٰدِقِينَ ﴾

“Many people think that they have bestowed a favour upon thee [O Prophet] by having surrendered [to thee]. Say thou: “Deem not your surrender a favour unto me: nay, but it is God who bestows a favour upon you by showing you the way to faith - if you are true to your word!””

Please check ayah 49:18 for complete tafsir.