Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
darimi:180Yazīd b. Hārūn > Ḥumayd > Abū Rajāʾ > Abū al-Muhallab > Abū Mūsá

[Machine] "In his sermon, he said: 'Whoever has knowledge should teach it to the people and himself, and should not speak about something he has no knowledge of, so as not to pass by the religion and be among the pretentious.'"  

الدارمي:١٨٠أَخْبَرَنَا يَزِيدُ بْنُ هَارُونَ حَدَّثَنَا حُمَيْدٌ عَنْ أَبِي رَجَاءٍ عَنْ أَبِي الْمُهَلَّبِ أَنَّ أَبَا مُوسَى قَالَ

فِي خُطْبَتِهِ «مَنْ عَلِمَ عِلْمًا فَلْيُعَلِّمْهُ النَّاسَ وَإِيَّاهُ أَنْ يَقُولَ مَا لَا عِلْمَ لَهُ بِهِ فَيَمْرُقُ مِنَ الدِّينِ وَيَكُونَ مِنَ الْمُتَكَلِّفِينَ»