"Abu Talhah married Umm Sulaim and the dowry between them was Islam. Umm Sulaim became Muslim before Abu Talhah, and he proposed to her but she said: 'I have become Muslim; if you become Muslim I will marry you.' So he became Muslim, and that was the dowry between them." (Using translation from Nasāʾī 3340)
تَزَوَّجَ أَبُو طَلْحَةَ أُمَّ سُلَيْمٍ وَكَانَ صَدَاقُ مَا بَيْنَهُمَا الْإِسْلَامُ أَسْلَمَتْ أُمُّ سُلَيْمٍ قَبْلَ أَبِي طَلْحَةَ فَخَطَبَهَا فَقَالَتْ «إِنِّي قَدْ أَسْلَمْتُ فِإِنْ أَسْلَمْتَ نَكَحْتُكَ» فَأَسْلَمَ فَكَانَ صَدَاقُ مَا بَيْنَهُمَا الْإِسْلَامُ