Sunan an-Nasa'i 3398
سنن النسائي#3398Sahihأَخْبَرَنِي زِيَادُ بْنُ أَيُّوبَ، قَالَ حَدَّثَنَا هُشَيْمٌ، قَالَ أَخْبَرَنَا أَبُو بِشْرٍ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ، عَنِ ابْنِ عُمَرَ، أَنَّهُ طَلَّقَ امْرَأَتَهُ وَهِيَ حَائِضٌ فَرَدَّهَا عَلَيْهِ رَسُولُ اللَّهِ صلى الله عليه وسلم حَتَّى طَلَّقَهَا وَهِيَ طَاهِرٌ .
It was narrated from Ibn 'Umar that he divorced his wife when she was menstruating, but the Messenger of Allah told him to take her back, and divorce her when she was pure (not menstruating)
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 27:10