أَخْبَرَنَا مُحَمَّدُ بْنُ يُوسُفَ ، عَنْ سُفْيَانَ ، أَنَّ عُمَرَ رَضِيَ اللهُ عَنْهُ، قَالَ لِكَعْبٍ :" مَنْ أَرْبَابُ الْعِلْمِ؟، قَالَ : الَّذِينَ يَعْمَلُونَ بِمَا يَعْلَمُونَ، قَالَ : فَمَا أَخْرَجَ الْعِلْمَ مِنْ قُلُوبِ الْعُلَمَاءِ؟، قَالَ : الطَّمَعُ "

Muhammad bin Yusuf told us, on the authority of Sufyan, that Omar, may God be pleased with him, said to Ka’b: “Who are the masters of knowledge?” He said: Those who work with They know. He said: What brought knowledge out of the hearts of scholars? He said: Greed.