Hadith 5752

'Ubaidullah bin Sa'eed said: "I heard Abu Usamah say: 'I never saw any man more assiduous in seeking knowledge than 'Abdullah bin Al-Mubarak, not in Ash-Sham, Egypt, Yemen or the Hijaz.'"

أَخْبَرَنَا عُبَيْدُ اللَّهِ بْنُ سَعِيدٍ، قَالَ سَمِعْتُ أَبَا أُسَامَةَ، يَقُولُ مَا رَأَيْتُ رَجُلاً أَطْلَبَ لِلْعِلْمِ مِنْ عَبْدِ اللَّهِ بْنِ الْمُبَارَكِ الشَّامَاتِ وَمِصْرَ وَالْيَمَنَ وَالْحِجَازَ ‏.‏

Reference: 1157380
In-book reference: Book 51, Hadith 5752
Hadith 5752 - The Book of Drinks - Sunan an-Nasa'i - Sunnah.com