Saad bin Abu Waqqas reported,

The Messenger of Allah ﷺ gave gifts to a group of men while Saad was sitting with him. The Messenger of Allah ﷺ left out one man whom I considered the most impressive of them.I said, "Messenger of Allah, what is the matter that you passed over so-and-so? By Allah, I consider him a believer."He replied, "Or a Muslim?"I remained silent for a moment, but what I knew of the man got the better of me, so I repeated my statement and said, "What is the matter that you passed over so-and-so? By Allah, I consider him a believer."He replied, "Or a Muslim?"Then what I knew of the man got the better of me again, so I repeated my statement, and the Messenger of Allah ﷺ repeated his.Then he said, "Saad, I give to a man while another is dearer to me than him, out of fear that Allah may cast him face down into the Fire."It was also narrated by Yunus, Salih, Muamar, and Ibn Akhi Zuhri from Zuhri.

Bukhari 27

Sahih

حدثنا أبو اليمان قال أخبرنا شعيب عن الزهري قال أخبرني عامر بن سعد بن أبي وقاص

عن سعد رضي الله عنه

أن رسول الله ﷺ أعطى رهطا وسعد جالس فترك رسول الله ﷺ رجلا هو أعجبهم إلي فقلت يا رسول الله ما لك عن فلان فوالله إني لأراه مؤمنا فقال أو مسلما فسكت قليلا ثم غلبني ما أعلم منه فعدت لمقالتي فقلت ما لك عن فلان فوالله إني لأراه مؤمنا فقال أو مسلما ثم غلبني ما أعلم منه فعدت لمقالتي وعاد رسول الله ﷺ ثم قال يا سعد إني لأعطي الرجل وغيره أحب إلي منه خشية أن يكبه الله في النار ورواه يونس وصالح ومعمر وابن أخي الزهري عن الزهري

البخاري 27صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Faith
Chapter
If Islam is not genuine and is based on submission or fear of being killed
Numbering
Darussalam 27
Bukhari 27