Marriage (Kitab Al-Nikah)
Dawud :: Book 11 : Hadith 2161
Narrated Aisha, Ummul Mu'minin:
I and the Apostle of Allah (peace_be_upon_him) used to lie in one cloth at night while I was menstruating. If anything from me smeared him, he washed the same place (that was smeared), and did not wash beyond it. If anything from him smeared his clothe, he washed the same place and did not wash beyond that, and prayed with it (i.e. the clothe).