I said, "Messenger of Allah, tell me something about Islam that I will not need to ask anyone else about."Abu Muawiya added in his version, "after you."He said, "Say, 'I believe in Allah,' then remain steadfast."
حدثنا وكيع وأبو معاوية قالا حدثنا هشام بن عروة عن أبيه
قلت يا رسول الله قل لي في الإسلام قولا لا أسأل عنه أحدا غيرك قال أبو معاوية بعدك قال قل آمنت بالله ثم استقم
Its isnad is sahih. It is found in Muslim 1/65, no. 38, in the Book of Faith, chapter, Compiling the Attributes of Islam, and in Tirmidhi 4/607, no. 2410, in the Book of Asceticism, chapter, What Has Been Said About Guarding the Tongue, where he said, hasan sahih, and in Ibn Majah 2/1314, no. 3972, and Darimi 2/386, no. 2711, and Ibn Hibban 6/32, no. 2543.