Sa'eed bin Musayyab and Abu Salamah bin 'Abdur-Rahman narrated that :Abu Hurairah used to say: "The Messenger of Allah said: 'When anyone of you wakes up from sleep, he should not put his hand into the vessel until he has poured water on it two or three times, for none of you knows where his hand spent the night
Hadith No. 393
Sunan Ibn Majah
Gradings:
Al-Albani:
Sahih
Muhammad Fouad Abd al-Baqi:
Sahih
Shuaib Al Arnaut:
Sahih
Zubair Ali Zai:
Sahih