A man said, "Messenger of Allah, the laws of Islam have become many for me, so tell me of something I can hold fast to."He replied, "Let your tongue remain moist with the remembrance of Allah."
أن رجلا قال: يا رسول الله إن شرائع الإسلام قد كثرت علي فأخبرني بشيء أتشبث به قال: لا يزال لسانك رطبا من ذكر الله.
Reported by Tirmidhi (3375), Ibn Majah (3793), and Ahmad (17680, 17698), and Ibn Hibban (814) and Hakim (1/495) graded it sahih, all of them through Amr bin Qays Kindi, from Abdullah bin Busr, who narrated it. Its chain is sahih, and Hakim graded it sahih. As for Tirmidhi, he said, "Hasan gharib from this route," because he reported it through Muawiya bin Salih, whose hadith is hasan, except that he was corroborated.