Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
darimi:1055ʿUbaydullāh b. Mūsá > ʿUthmān > Mujāhid

[Machine] The menstruating woman prays in the same clothes she menstruates in, except if any blood specifically touches the clothes, then she washes the spot where the blood is.  

الدارمي:١٠٥٥أَخْبَرَنَا عُبَيْدُ اللَّهِ بْنُ مُوسَى عَنْ عُثْمَانَ عَنْ مُجَاهِدٍ قَالَ

الْمَرْأَةُ «الْحَائِضُ تُصَلِّي فِي ثِيَابِهَا الَّتِي تَحِيضُ فِيهَا إِلَّا أَنْ يُصِيبَ شَيْئًا مِنْهَا دَمٌ فَتَغْسِلَ مَوْضِعَ الدَّمِ»