Sunan an-Nasa'i, Volume 3, Book 22, Hadith 2150 (DarusSalam) ⓘ
It was narrated that Abu Hurairah said: "Eat Sahur, for in Sahur there is blessing." (Sahih Mawquf) while Ibn Abi Laila narrated it in Marfu form:
أَخْبَرَنَا أَحْمَدُ بْنُ سُلَيْمَانَ، قَالَ حَدَّثَنَا يَزِيدُ، قَالَ أَنْبَأَنَا عَبْدُ الْمَلِكِ بْنُ أَبِي سُلَيْمَانَ، عَنْ عَطَاءٍ، عَنْ أَبِي هُرَيْرَةَ، قَالَ تَسَحَّرُوا فَإِنَّ فِي السَّحُورِ بَرَكَةً . رَفَعَهُ ابْنُ أَبِي لَيْلَى .
also referenced under: Hadith 2148 (Reference) & Book 22, Hadith 59 (In-Book)