كتاب المقدمات
The Book of Miscellany
(7)
Chapter: Firm Belief and Perfect Reliance on Allah
(7)
- باب اليقين والتوكل
Riyad as-Salihin 84
Anas (May Allah be pleased with him) reported:
There were two brothers in the days of the Prophet (ﷺ). One of them used to attend the Prophet's circle (to acquire knowledge) and the other used to earn their living). Once the latter complained to the Prophet (ﷺ) against the former (for not earning his living). He (ﷺ) replied, "Perhaps you are being provided because of him".

[At- Tirmidhi, who said it has a sound chain].

وعن أنس رضي الله عنه قال‏:‏ كان أخوان على عهد النبي صلى الله عليه وسلم، وكان أحدهما يأتي النبي صلى الله عليه وسلم ، والآخر يحترف، فشكا المحترف آخاه للنبي صلى الله عليه وسلم فقال ‏:‏ ‏ "‏لعلك ترزق به‏"‏ ‏(‏‏(‏رواه الترمذي بإسناد صحيح على شرط مسلم‏)‏‏)‏‏.‏
Reference : Riyad as-Salihin 84
In-book reference : Introduction, Hadith 84