Sahih Muslim , Book 12, Hadith 86 (In-Book) ⓘ

'Adi b. Hatim reported that the Messenger of Allah made a mention of Fire. He turned his face aside and diverted his attention and then said: Guard (yourselves) against Fire. He turned his face and diverted his attention till we thought as if he were (actually seeing it and then said: Protect yourselves against Fire even if it is with half a date, and he who does not find it, (he should do so) with pleasant words. Abu Kuraib did not mention the word: (as if).

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، وَأَبُو كُرَيْبٍ قَالاَ حَدَّثَنَا أَبُو مُعَاوِيَةَ، عَنِ الأَعْمَشِ، عَنْ عَمْرِو بْنِ مُرَّةَ، عَنْ خَيْثَمَةَ، عَنْ عَدِيِّ بْنِ حَاتِمٍ، قَالَ ذَكَرَ رَسُولُ اللَّهِ صلى الله عليه وسلم النَّارَ فَأَعْرَضَ وَأَشَاحَ ثُمَّ قَالَ ‏"‏ اتَّقُوا النَّارَ ‏"‏ ‏.‏ ثُمَّ أَعْرَضَ وَأَشَاحَ حَتَّى ظَنَنَّا أَنَّهُ كَأَنَّمَا يَنْظُرُ إِلَيْهَا ثُمَّ قَالَ ‏"‏ اتَّقُوا النَّارَ وَلَوْ بِشِقِّ تَمْرَةٍ فَمَنْ لَمْ يَجِدْ فَبِكَلِمَةٍ طَيِّبَةٍ ‏"‏ ‏.‏ وَلَمْ يَذْكُرْ أَبُو كُرَيْبٍ كَأَنَّمَا وَقَالَ حَدَّثَنَا أَبُو مُعَاوِيَةَ حَدَّثَنَا الأَعْمَشُ ‏.‏