[Machine] It is reported that the daughter of Ja'hsh informed the Prophet Muhammad ﷺ that she used to have irregular bleeding during her period. The Prophet ﷺ instructed her to perform a ritual purification (ghusl) for every prayer. If she noticed that blood was entering her vagina while inside the mosque, and she found water inside the mosque, she should submerge herself in it and then exit. If the blood was on top of the water, she should pray without repeating the purification.
أَنَّ ابْنَةَ جَحْشٍ «اسْتُحِيضَتْ عَلَى عَهْدِ رَسُولِ اللَّهِ ﷺ فَأَمَرَهَا رَسُولُ اللَّهِ ﷺ بِالْغُسْلِ لِكُلِّ صَلَاةٍ فَإِنْ كَانَتْ لَتَدْخُلُ الْمِرْكَنَ وَإِنَّهُ لَمَمْلُوءٌ مَاءً فَتَنْغَمِسُ فِيهِ ثُمَّ تَخْرُجُ مِنْهُ وَإِنَّ الدَّمَ فَوْقَهُ لَغَالبُهُ فَتُصَلِّي»