حَدَّثَنَا أَبُو بَكْرِ بْنُ خَلاَّدٍ الْبَاهِلِيُّ، حَدَّثَنَا سُفْيَانُ، عَنْ أَبِي الزِّنَادِ، عَنِ الْقَاسِمِ بْنِ مُحَمَّدٍ، قَالَ ذَكَرَ ابْنُ عَبَّاسٍ الْمُتَلاَعِنَيْنِ ‏.‏ فَقَالَ لَهُ ابْنُ شَدَّادٍ هِيَ الَّتِي قَالَ لَهَا رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ لَوْ كُنْتُ رَاجِمًا أَحَدًا بِغَيْرِ بَيِّنَةٍ لَرَجَمْتُهَا ‏"‏ ‏.‏ فَقَالَ ابْنُ عَبَّاسٍ تِلْكَ امْرَأَةٌ أَعْلَنَتْ ‏.‏

It was narrated that Qasim bin Muhammad said: “Ibn `Abbas mentioned two people who had engaged in the process of Li`an. Ibn Shaddad said to him: 'Is this the one of whom the Messenger of Allah (PBUH) said: “If I were to stone anyone without proof I would have stoned so-and-so.” Ibn`Abbas said: 'No, that was a woman who, (although she was a Muslim), used to expose herself.'” Translation Not Available

Book Ref: Sunan Ibn Majah Book 20 Hadith 2560
Web Ref:  Sunan Ibn Majah Vol 3 Book 20 Hadith 2560