كتاب الزكاة
12  
The Book of Zakat
(20)
Chapter: Encouragement to give charity even if it is with half a date or a kind word. And charity is a shield against the fire.
(20)
باب الْحَثِّ عَلَى الصَّدَقَةِ وَلَوْ بِشِقِّ تَمْرَةٍ أَوْ كَلِمَةٍ طَيِّبَةٍ وَأَنَّهَا حِجَابٌ مِنْ النَّارِ
Sahih Muslim 1016 d

Adi b. Hatim reported that the Messenger of Allah (ﷺ) made a mention of the Fire and sought refuge (with Allah against it). He turned aside his face three times and then said:

Protect yourselves against Fire even if with half a date. But if you fail to find it (then protect yourselves against Fire) with the help of a pleasant word).
وَحَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، وَابْنُ، بَشَّارٍ قَالاَ حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، حَدَّثَنَا شُعْبَةُ، عَنْ عَمْرِو بْنِ مُرَّةَ، عَنْ خَيْثَمَةَ، عَنْ عَدِيِّ بْنِ حَاتِمٍ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم أَنَّهُ ذَكَرَ النَّارَ فَتَعَوَّذَ مِنْهَا وَأَشَاحَ بِوَجْهِهِ ثَلاَثَ مِرَارٍ ثُمَّ قَالَ ‏ "‏ اتَّقُوا النَّارَ وَلَوْ بِشِقِّ تَمْرَةٍ فَإِنْ لَمْ تَجِدُوا فَبِكَلِمَةٍ طَيِّبَةٍ ‏"‏ ‏.‏
Reference : Sahih Muslim 1016d
In-book reference : Book 12, Hadith 87
USC-MSA web (English) reference : Book 5, Hadith 2218
  (deprecated numbering scheme)