﴿ 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!””

They deem it to be a favour to you that they have submitted without the need for any fighting unlike those others who submitted only after being fought. Say ‘Do not deem your submission to be a favour to me islāmakum ‘your submission’ has dependent accusative status because of the omission of the genitive preposition bi-which is also read as implicit before the an in both instances. Rather it is God Who has done you a favour in that He has guided you to faith if you are being sincere when you say ‘We believe’.