(3) بَاب فَضْلِ دَوَامِ الذِّكْرِ وَالْفِكْرِ فِي أُمُورِ الْآخِرَةِ وَالْمُرَاقَبَةِ وَجَوَازِ تَرْكِ ذَلِكَ فِي بَعْضِ الْأَوْقَاتِ وَالِاشْتِغَالِ بِالدُّنْيَا
Hanzala Taimi Ufayyidi, the scribe of Allah's Messenger (ﷺ), reported:
We were in the presence of Allah's Messenger (ﷺ) and he brought to our minds the problems pertaining to Paradise and Hell-Fire. The rest of the hadith is the same.
Reference: Sahih Muslim 2750 c
In-book reference: Book 50, Hadith 16
USC-MSA web (English) reference(deprecated numbering scheme): Book 37, Hadith 6625