Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) said: Knowledge is of three kinds: a speaking Book, an established Sunnah, and saying: I do not know.
Al-Tabarani recorded it in al-Mu'jam al-Awsat; its chain contains a narrator, Husayn, whose lineage is not mentioned. He narrated it from Imam Malik, and Ibrahim bin al-Mundhir narrated it from him. I have not seen anyone who has written a biography of him.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب العلم / 801
Hadith Gradingمحدثین:إسنادہ ضعیف؛ اس کی سند میں حصین نامی راوی غیر معروف
Hadith Takhrij«اخرجه الامام الطبراني فى معجم الاوسط 1001»