Sunan an-Nasa'i, Hadith 2552 ⓘ
It was narrated from 'Adiyy bin Hatim that the Prophet said: "Protect yourselves from the Fire, even with half a date."
أَخْبَرَنَا نَصْرُ بْنُ عَلِيٍّ، عَنْ خَالِدٍ، حَدَّثَنَا شُعْبَةُ، عَنِ الْمُحِلِّ، عَنْ عَدِيِّ بْنِ حَاتِمٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " اتَّقُوا النَّارَ وَلَوْ بِشِقِّ تَمْرَةٍ " .
also referenced under: Book 23, Hadith 0 (In-Book) & Volume 3, Book 23, Hadith 2553 (DarusSalam)