It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Holy Prophet (peace and blessings of Allah be upon him) said: The one who serves widows and the poor is like a warrior in the way of Allah, or like the person who spends the whole night in prayer and the whole day in fasting.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 8732
Hadith Gradingحکم دارالسلام:صحيح، وهذا إسناد قوي، خ: 5353، م: 2982