From Abu Hurairah (radiyallaahu 'anhu) who said that Allaah's Messenger (salallaahu 'alaihi wa'sallam) said:
Charity (sadaqah) is due upon every joint of a person on every day that the sun rises. Administering justice between two people is an act of charity; and to help a man concerning his riding beast by helping him on to it or lifting his luggage on to it is an act of charity; a good word is charity; and every step which you take to prayer is charity; and removing that which is harmful from the road is charity.
So if the servant is able to spend all his days and nights in obedience to Allaah, and in doing actions pleasing to Him, then let him do so!
[Author's text abridged hereafter]
Even though abstemiousness is to be given special attention by the rich due to their ability to spend and their wealth, as opposed to the poor, then this will not prevent the Muslim, rich or poor, from having a contented and rich soul, since: