Messenger of Allah ﷺ said, "The one who looks after and works for a widow and for a poor person is like a warrior fighting for Allah's Cause." (The narrator Al-Qa'nabi is not sure whether he also said "Like the one who prays all the night without slackness and fasts continuously and never breaks his fast.")  

قَالَ رَسُولُ اللَّهِ ﷺ السَّاعِي عَلَى الأَرْمَلَةِ وَالْمِسْكِينِ كَالْمُجَاهِدِ فِي سَبِيلِ اللَّهِ وَأَحْسِبُهُ قَالَ يَشُكُّ الْقَعْنَبِيُّ كَالْقَائِمِ لاَ يَفْتُرُ وَكَالصَّائِمِ لاَ يُفْطِرُ  

that Messenger of Allah ( ﷺ) said: One who makes efforts (for earning to be spent) on a widow and the destitute is like a striver in the cause of Allah, and I think he also said: He is like one who constantly stands for prayer and observes fast without breaking it.  

عَنِ النَّبِيِّ ﷺ قَالَ: «السَّاعِي عَلَى الأَرْمَلَةِ وَالْمِسْكِينِ كَالْمُجَاهِدِ فِي سَبِيلِ اللَّهِ۔» وَأَحْسِبُهُ قَالَ: «وَكَالْقَائِمِ لاَ يَفْتُرُ وَكَالصَّائِمِ لاَ يُفْطِرُ۔»  

[Machine] Narrated Abu Huraira:

The Messenger of Allah ﷺ said, "The one who cares for the widow and the poor is like a fighter in the cause of Allah." And I consider him to have said, "Like the one who fasts and does not break his fast, and like the one who stands in prayer and does not sleep."  

حَدَّثَنَا الْقَعْنَبِيُّ عَنْ مَالِكٍ عَنْ ثَوْرِ بْنِ زَيْدٍ عَنْ أَبِي الْغَيْثِ عَنْ أَبِي هُرَيْرَةَ قَالَ قَالَ رَسُولُ اللَّهِ ﷺ «السَّاعِي عَلَى الْأَرْمَلَةِ وَالْمِسْكِينِ كَالْمُجَاهِدِ فِي سَبِيلِ اللَّهِ» وَأَحْسِبُهُ قَالَ «كَالصَّائِمِ لَا يُفْطِرُ وَكَالْقَائِمِ لَا يَنَامُ»