Sunan an-Nasa'i, Volume 3, Book 22, Hadith 2164 (DarusSalam) ⓘ
'Abdullah bin Al-Harith narrated that a man from among the Companions of th Prophet said: "I entered upon the Prophet when he was having Sahur. He sadi: 'It is a blessing that Allah has given to you, so do not neglect it."
أَخْبَرَنَا إِسْحَاقُ بْنُ مَنْصُورٍ، قَالَ أَنْبَأَنَا عَبْدُ الرَّحْمَنِ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنْ عَبْدِ الْحَمِيدِ، صَاحِبِ الزِّيَادِيِّ قَالَ سَمِعْتُ عَبْدَ اللَّهِ بْنَ الْحَارِثِ، يُحَدِّثُ عَنْ رَجُلٍ، مِنْ أَصْحَابِ النَّبِيِّ صلى الله عليه وسلم قَالَ دَخَلْتُ عَلَى النَّبِيِّ صلى الله عليه وسلم وَهُوَ يَتَسَحَّرُ فَقَالَ " إِنَّهَا بَرَكَةٌ أَعْطَاكُمُ اللَّهُ إِيَّاهَا فَلاَ تَدَعُوهُ " .
also referenced under: Hadith 2162 (Reference) & Book 22, Hadith 73 (In-Book)