(a) Aws bin Abi Aws (may Allah be pleased with him) says: I saw the Messenger of Allah (peace and blessings be upon him) performing ablution, and he (peace and blessings be upon him) filled his palms three times.
(b) Shu'bah says: I asked al-Nu'man: What is meant by filling the palms? He said: He (peace and blessings be upon him) washed his palms three times.
(c) Adam bin Abi Iyas has established its chain soundly; in its chain there is disagreement only over Shu'bah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 210