Sahih Bukhari Volume 2, Book 11, Hadith 901

حَدَّثَنَا يُوسُفُ بْنُ مُوسَى، حَدَّثَنَا أَبُو أُسَامَةَ، حَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ عُمَرَ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، قَالَ كَانَتِ امْرَأَةٌ لِعُمَرَ تَشْهَدُ صَلاَةَ الصُّبْحِ وَالْعِشَاءِ فِي الْجَمَاعَةِ فِي الْمَسْجِدِ، فَقِيلَ لَهَا لِمَ تَخْرُجِينَ وَقَدْ تَعْلَمِينَ أَنَّ عُمَرَ يَكْرَهُ ذَلِكَ وَيَغَارُ قَالَتْ وَمَا يَمْنَعُهُ أَنْ يَنْهَانِي قَالَ يَمْنَعُهُ قَوْلُ رَسُولِ اللَّهِ صلى الله عليه وسلم ‏"‏ لاَ تَمْنَعُوا إِمَاءَ اللَّهِ مَسَاجِدَ اللَّهِ ‏"‏‏

Narrated By Ibn Umar : One of the wives of Umar (bin Al-Khattab) used to offer the Fajr and the 'Isha prayer in congregation in the Mosque. She was asked why she had come out for the prayer as she knew that Umar disliked it, and he has great ghaira (self-respect). She replied, "What prevents him from stopping me from this act?" The other replied, "The statement of Allah's Apostle (p.b.u.h) : 'Do not stop Allah's women-slave from going to Allah s Mosques' prevents him."