Sahih al-Bukhari, Book 69, Hadith 3 (In-Book) ⓘ
Narrated Abu Huraira: The Prophet said, "The one who looks after a widow or a poor person is like a Mujahid (warrior) who fights for Allah's Cause, or like him who performs prayers all the night and fasts all the day."
حَدَّثَنَا يَحْيَى بْنُ قَزَعَةَ، حَدَّثَنَا مَالِكٌ، عَنْ ثَوْرِ بْنِ زَيْدٍ، عَنْ أَبِي الْغَيْثِ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ النَّبِيُّ صلى الله عليه وسلم " السَّاعِي عَلَى الأَرْمَلَةِ وَالْمِسْكِينِ كَالْمُجَاهِدِ فِي سَبِيلِ اللَّهِ، أَوِ الْقَائِمِ اللَّيْلَ الصَّائِمِ النَّهَارَ " .
also referenced under: Hadith 5353 (DarusSalam) & Volume 7, Book 64, Hadith 265 (USC-MSA)