Abu Dawud
Purification (Kitab Al-Taharah)
Book Number: 001 / Hadith Number: 357
Narated By Mu'adhah : 'Aisha was asked about (washing) the clothes of menstruating woman smeared with blood. She said: She should wash it; in case the mark is not removed she should change it by applying some yellow colour. I had three menstruations together while I lived with the Apostle of Allah (pbuh), but I did not wash my clothes.