أَخْبَرَنَا يَزِيدُ بْنُ هَارُونَ ، حَدَّثَنَا حُمَيْدٌ ، عَنْ أَبِي رَجَاءٍ ، عَنْ أَبِي الْمُهَلَّبِ ، أَنَّ أَبَا مُوسَى رَضِيَ اللهُ عَنْهُ، قَالَ فِي خُطْبَتِهِ :" مَنْ عَلِمَ عِلْمًا، فَلْيُعَلِّمْهُ النَّاسَ، وَإِيَّاهُ أَنْ يَقُولَ مَا لَا عِلْمَ لَهُ بِهِ فَيَمْرُقَ مِنْ الدِّينِ وَيَكُونَ مِنْ الْمُتَكَلِّفِينَ "

Yazid bin Harun told us, Humaid told us, on the authority of Abu Raja’, on the authority of Abu Al-Muhallab, that Abu Musa, may God be pleased with him, said in His sermon: “Whoever knows knowledge, let him teach it to people, and beware of saying something of which he has no knowledge, then he will depart from the religion and become one of those who are indifferent.”