The prohibition of divorcing a menstruating woman without her consent; If a man breaks this rule, it still counts as a divorce, and he should be ordered to take her back
وَحَدَّثَنِيهِ إِسْحَاقُ بْنُ مَنْصُورٍ، أَخْبَرَنَا يَزِيدُ بْنُ عَبْدِ رَبِّهِ، حَدَّثَنَا مُحَمَّدُ بْنُ حَرْبٍ، حَدَّثَنِي الزُّبَيْدِيُّ، عَنِ الزُّهْرِيِّ، بِهَذَا الإِسْنَادِ غَيْرَ أَنَّهُ قَالَ قَالَ ابْنُ عُمَرَ فَرَاجَعْتُهَا وَحَسَبْتُ لَهَا التَّطْلِيقَةَ الَّتِي طَلَّقْتُهَا .
A hadith like this was reported on the authority of Zuhri with the same chain of narrators. Ibn Umar (Allah be pleased with them), however, said: I took her back, and counted this pronouncement of divorce (as valid) with which I divorced her.