The Prophet (sallallaahu alalyhi wa sallam) said:
Al-saa'i [the one who looks after the welfare, provision, and other necessary affairs] of the ‘armalah [widow] and miskiin [poor] is like the one who does Jihaad [Mujaahid] in the way of Allaah or like the one who stands all night [in prayer] and fasts all day.
[Sahih al-Bukhaari Hadith No. 5353]
The one who is unable to perform Jihaad in the way of Allaaah, stand during the night in prayer, and fast during the day then let him act according to this Hadiith, and let him look after the 'armalah and the poor so that he is resurrected on the Day of Judgment among those who do Jihaad in the way of Allaah without taking a step for that, without spending a dirham, and without meeting any enemy who frightens him or so that he may be resurrected among those who fast and stand in prayer and reach their ranks while he ate during the day and slept during the nights.
It is fitting for every believer to recommend this trade which will not perish and look after the widows or poor for the sake of Allaah and then get dividends from his trade in the form of the ranks of those who do Jihaad, fast and stand in prayer without having to exert or fatigue himself. That is the blessing of Allaah which He blesses whom He wills with.
Volume 9 Page 218
Sharh al-Bukhaari by Ibn Battaal