The Messenger of Allah said: "There is no ablution for one who does not mention the Name of Allah (before doing it)."
Sunan Ibn Majah Book 1, Hadith 131
← Previous Hadith "'Ali called for water, and he washed his hands before putting them in the vessel, then he said: 'This is what I saw the Messenger of Allah doing.'"

Sunan Ibn Majah Book 1, Hadith 130 Next Hadith → "The Messenger of Allah said: 'There is no prayer for one who does not have ablution, and there is no ablution for one who does not mention the Name of Allah (before it).'"

Sunan Ibn Majah Book 1, Hadith 132