Sunan an-Nasa'i, Book 2, Hadith 21 (In-Book) ⓘ
It was narrated that 'Abdullah bin Jabr said: "I heard Anas bin Malik say: 'The Messenger of Allah used to perform Wudu' with a Makkuk (cup) and Ghusl with five Makkuks (cups).'"
أَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، قَالَ حَدَّثَنَا شُعْبَةُ، قَالَ حَدَّثَنِي عَبْدُ اللَّهِ بْنُ عَبْدِ اللَّهِ بْنِ جَبْرٍ، قَالَ سَمِعْتُ أَنَسَ بْنَ مَالِكٍ، يَقُولُ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَتَوَضَّأُ بِمَكُّوكٍ وَيَغْتَسِلُ بِخَمْسَةِ مَكَاكِيَّ .
also referenced under: Hadith 345 (Reference) & Volume 1, Book 2, Hadith 346 (DarusSalam)