Sunan an-Nasa'i, Volume 3, Book 23, Hadith 2554 (DarusSalam) ⓘ

It was narrated that 'Adiyy bin Hatim said: "The Messenger of Allah mentioned the Fire, and he turned his face away (as if seeing it), and sought refuge with Allah from it." (One of the narrators) Shu'bah said: "He did that three times, then he said: 'Protect yourselves from the Fire even with half a date, and if you cannot find that, then with a good word."'

أَنْبَأَنَا إِسْمَاعِيلُ بْنُ مَسْعُودٍ، قَالَ حَدَّثَنَا خَالِدٌ، قَالَ حَدَّثَنَا شُعْبَةُ، أَنَّ عَمْرَو بْنَ مُرَّةَ، حَدَّثَهُمْ عَنْ خَيْثَمَةَ، عَنْ عَدِيِّ بْنِ حَاتِمٍ، قَالَ ذَكَرَ رَسُولُ اللَّهِ صلى الله عليه وسلم النَّارَ فَأَشَاحَ بِوَجْهِهِ وَتَعَوَّذَ مِنْهَا ذَكَرَ شُعْبَةُ أَنَّهُ فَعَلَهُ ثَلاَثَ مَرَّاتٍ - ثُمَّ قَالَ ‏ "‏ اتَّقُوا النَّارَ وَلَوْ بِشِقِّ التَّمْرَةِ فَإِنْ لَمْ تَجِدُوا فَبِكَلِمَةٍ طَيِّبَةٍ ‏" ‏ ‏.‏