Sunan Ibn Majah, Book 1, Hadith 428 (In-Book) ⓘ
It was narrated that Harith said: "'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.'"
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا أَبُو بَكْرِ بْنُ عَيَّاشٍ، عَنْ أَبِي إِسْحَاقَ، عَنِ الْحَارِثِ، قَالَ دَعَا عَلِيٌّ بِمَاءٍ فَغَسَلَ يَدَيْهِ قَبْلَ أَنْ يُدْخِلَهُمَا الإِنَاءَ ثُمَّ قَالَ هَكَذَا رَأَيْتُ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ صَنَعَ .
also referenced under: Hadith 396 (Reference) & Volume 1, Book 1, Hadith 396 (DarusSalam)