Sunan an-Nasai 15125
In-book no 389أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا الْفُضَيْلُ، - وَهُوَ ابْنُ عِيَاضٍ - عَنِ الأَعْمَشِ، عَنْ تَمِيمِ بْنِ سَلَمَةَ، عَنْ عُرْوَةَ، عَنْ عَائِشَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يُخْرِجُ رَأْسَهُ مِنَ الْمَسْجِدِ وَهُوَ مُعْتَكِفٌ فَأَغْسِلُهُ وَأَنَا حَائِضٌ .
It was narrated from 'Aishah: "The Messenger of Allah (ﷺ) used to put his head out of the Masjid while he was performing I'tikaf, and I would wash it, while I was menstruating."