Sunan an-Nasa'i, Hadith 2149 ⓘ
It was narrated from Abu Hurairah that the Prophet said: "Take Sahur, for in Sahur there is blessing."
أَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ حَدَّثَنَا يَحْيَى، قَالَ حَدَّثَنَا ابْنُ أَبِي لَيْلَى، عَنْ عَطَاءٍ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " تَسَحَّرُوا فَإِنَّ فِي السَّحُورِ بَرَكَةً " .
also referenced under: Book 22, Hadith 60 (In-Book) & Volume 3, Book 22, Hadith 2151 (DarusSalam)