From the route of Abu Dharr, may Allah accept his deeds, who said that some people among the Companions of the Prophet, sallallahu ^alayhi wa sallam, asked the Prophet, sallallahu ^alayhi wa sallam: O Messenger of Allah the wealthy people have engulfed the rewards, they pray as we do, fast as we do and spend their excess money in charity.
The Prophet said, << Is it not the case that Allah has provided you that which you can spend in charity? There is a charity in every Subhanallah one says, and every Allah Akbar one says, and every al-Hamdulillah one says, and every la ilaha illallah one says, and every lawful matter one orders, and every unlawful matter one prohibits, and every sexual intercourse with ones lawful woman.>>
They said: O Messenger of Allah, would one be rewardable for having sexual intercourse with ones lawful woman?
The Prophet answered, <<Do you not observe that if one had sexual intercourse with an unlawful woman one would be sinful, likewise if one would have sexual intercourse with one’s lawful woman one would be rewardable.>>
Narrated by Muslim.