Sunan Abi Dawud

Narrated 'Abdullah b. 'Umar: The Apostle of Allaah ( sal Allaahu alayhi wa sallam ) said: When there is enough water to fill two pitchers, it does not become impure. Abu Dawud said : Hammad b. Zaid has narrated this tradition on the authority of 'Asim ( without any reference to the Prophet)