The Mahr in the case Li‘an

Narrated Said bin Jubair:

I asked Ibn 'Umar, "(What is the verdict if) a man accuses his wife of illegal sexual intercourse?" Ibn 'Umar said, "The Prophet separated (by divorce) the couple of Bani Al-Ajlan, and said, (to them), 'Allah knows that one of you two is a liar;
so will one of you repent?' But both of them refused. He again said, 'Allah knows that one of you two is a liar;
so will one of you repent?' But both of them refused. So he separated them by divorce." (Aiyub, a sub-narrator said: 'Amr bin Dinar said to me, "There is something else in this Hadith which you have not mentioned. It goes thus: The man said, 'What about my money (i.e. the Mahr that I have given to my wife)?' It was said, 'You have no right to restore any money, for if you have spoken the truth (as regards the accusation), you have also consummated your marriage with her;
and if you have told a lie, you are less rightful to have your money back.' ")

حَدَّثَنِي عَمْرُو بْنُ زُرَارَةَ، أَخْبَرَنَا إِسْمَاعِيلُ، عَنْ أَيُّوبَ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ، قَالَ قُلْتُ لاِبْنِ عُمَرَ رَجُلٌ قَذَفَ امْرَأَتَهُ فَقَالَ فَرَّقَ النَّبِيُّ ﷺ بَيْنَ أَخَوَىْ بَنِي الْعَجْلاَنِ، وَقَالَ " اللَّهُ يَعْلَمُ أَنَّ أَحَدَكُمَا كَاذِبٌ، فَهَلْ مِنْكُمَا تَائِبٌ ". فَأَبَيَا. وَقَالَ " اللَّهُ يَعْلَمُ أَنَّ أَحَدَكُمَا كَاذِبٌ، فَهَلْ مِنْكُمَا تَائِبُ ". فَأَبَيَا. فَقَالَ " اللَّهُ يَعْلَمُ أَنَّ أَحَدَكُمَا كَاذِبٌ، فَهَلْ مِنْكُمَا تَائِبٌ " فَأَبَيَا فَفَرَّقَ بَيْنَهُمَا. قَالَ أَيُّوبُ فَقَالَ لِي عَمْرُو بْنُ دِينَارٍ إِنَّ فِي الْحَدِيثِ شَيْئًا لاَ أَرَاكَ تُحَدِّثُهُ قَالَ قَالَ الرَّجُلُ مَالِي قَالَ قِيلَ لاَ مَالَ لَكَ، إِنْ كُنْتَ صَادِقًا فَقَدْ دَخَلْتَ بِهَا، وَإِنْ كُنْتَ كَاذِبًا فَهْوَ أَبْعَدُ مِنْكَ.