ENOfficial
Abū Huraira reported God’s messenger as saying, “Expound the Qur’ān and take as guide its unusual expressions, they being the things made obligatory in it and the limits set in it.” Transmitted by Baihaqī in Shu'ab al-īmān.
Source: sunnah.com
Other translations
Arabic
وَعَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «أَعْرِبُوا الْقُرْآنَ وَاتَّبِعُوا غَرَائِبَهُ وَغَرَائِبُهُ فَرَائِضُهُ وَحُدُودُهُ» . رَوَاهُ الْبَيْهَقِيّ فِي شعب الْإِيمَان
sunnah.com