وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ أَبِيهِ، أَنَّهُ قَالَ كَانَ الرَّجُلُ إِذَا طَلَّقَ امْرَأَتَهُ ثُمَّ ارْتَجَعَهَا قَبْلَ أَنْ تَنْقَضِيَ عِدَّتُهَا كَانَ ذَلِكَ لَهُ وَإِنْ طَلَّقَهَا أَلْفَ مَرَّةٍ فَعَمَدَ رَجُلٌ إِلَى امْرَأَتِهِ فَطَلَّقَهَا حَتَّى إِذَا شَارَفَتِ انْقِضَاءَ عِدَّتِهَا رَاجَعَهَا ثُمَّ طَلَّقَهَا ثُمَّ قَالَ لاَ وَاللَّهِ لاَ آوِيكِ إِلَىَّ وَلاَ تَحِلِّينَ أَبَدًا ‏.‏ فَأَنْزَلَ اللَّهُ تَبَارَكَ وَتَعَالَى ‏{‏الطَّلاَقُ مَرَّتَانِ فَإِمْسَاكٌ بِمَعْرُوفٍ أَوْ تَسْرِيحٌ بِإِحْسَانٍ‏}‏ فَاسْتَقْبَلَ النَّاسُ الطَّلاَقَ جَدِيدًا مِنْ يَوْمِئِذٍ مَنْ كَانَ طَلَّقَ مِنْهُمْ أَوْ لَمْ يُطَلِّقْ ‏.‏

Yahya related to me from Malik from Hisham ibn Urwa that hisfather said, "It used to be that a man would divorce his wife and thenreturn to her before her idda was over, and that was alright, even ifhe divorced her a thousand times. The man went to his wife and thendivorced her and when the end of her idda was in sight, he took herback and then divorced her and said, 'No! By Allah, I will not go toyou and you will never be able to marry again.' Allah, the Blessed,the Exalted, sent down, 'Divorce is twice, then honourable retentionor setting free kindly.' People then turned towards divorce in a newlight from that day whether or not they were divorced or notdivorced." Translation Not Available

Book Ref: Muwatta Imam Malik Book 29 Hadith 1242
Web Ref:  Muwatta Imam Malik Book 29 Hadith 80