The Messenger of Allah ﷺ said, "What I fear most for my nation is every hypocrite with an Aleem tongue."
حدثنا أبو سعيد حدثنا ديلم بن غزوان عبدي حدثنا ميمون الكردي حدثني أبو عثمان النهدي
أن رسول الله ﷺ قال إن أخوف ما أخاف على أمتي كل منافق عليم اللسان
Its chain of transmission is sahih. Abu Uthman is Nahdi, Abdul-Rahman bin Mill. Maymun the Kurd was deemed reliable by Abu Dawud, Ibn Hibban, and others. Daylam bin Ghazwan was deemed reliable by Ibn Main, Ibn Hibban, and others. In H it appears as "Waylam" with a waw, which is an error, the correct form being "Daylam" with a dal. The hadith will follow as no. 310.