An-Nawawi's 40 Hadith 21
الأربعون النووية#21Not gradedعَنْ أَبِي عَمْرٍو وَقِيلَ: أَبِي عَمْرَةَ سُفْيَانَ بْنِ عَبْدِ اللَّهِ رَضِيَ اللهُ عَنْهُ قَالَ: قُلْت: يَا رَسُولَ اللَّهِ! قُلْ لِي فِي الْإِسْلَامِ قَوْلًا لَا أَسْأَلُ عَنْهُ أَحَدًا غَيْرَك؛ قَالَ: قُلْ: آمَنْت بِاَللَّهِ ثُمَّ اسْتَقِمْ . [رَوَاهُ مُسْلِمٌ]
On the authority of Abu `Amr — and he is also called Abu `Amrah — Sufyan bin Abdullah ath- Thaqafee (may Allah be pleased with him) who said: I said, "O Messenger of Allah, tell me something about al-Islam which I can ask of no one but you." He (peace and blessings of Allah be upon him) said, "Say I believe in Allah — and then be steadfast." [Muslim]
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Our source carries no per-scholar grade for this narration. Please verify on Sunnah.com or with a qualified scholar before relying on it.
In-book reference: 1:21