3. This is illustrated in a hadith recorded by Imam
    Muslim in his Sahih, in which it is related on the authority of Abu Dharr that the Prophet
    Muhammad  said, "You will
    receive the reward for sadaqa even when you have sexual intercourse with your wives."
    The sahaba said, "Will we really be rewarded for satisfying our physical
    desires?" He replied, "If you have haram intercourse, you will be committing a
    sin; similarly, if you have halal intercourse, you will be rewarded." Imam an-Nawawi said, 
"This hadith clearly shows that permissible actions become acts of 
obedience if there is a good intentino behind them; sexual intercourse becomes 
an act of worship if it is accompanied by any one of the following good 
intentions: keeping company with your wife in kindness, as Allah ta'Ala has 
commanded; hoping to hate, as a result of intercourse, good and righteous 
offsping; guarding your chastity and that of your wife; helping to prevent haram 
lustful glances or thoughts, or haram intercourse; and any other good 
intention."
 said, "You will
    receive the reward for sadaqa even when you have sexual intercourse with your wives."
    The sahaba said, "Will we really be rewarded for satisfying our physical
    desires?" He replied, "If you have haram intercourse, you will be committing a
    sin; similarly, if you have halal intercourse, you will be rewarded." Imam an-Nawawi said, 
"This hadith clearly shows that permissible actions become acts of 
obedience if there is a good intentino behind them; sexual intercourse becomes 
an act of worship if it is accompanied by any one of the following good 
intentions: keeping company with your wife in kindness, as Allah ta'Ala has 
commanded; hoping to hate, as a result of intercourse, good and righteous 
offsping; guarding your chastity and that of your wife; helping to prevent haram 
lustful glances or thoughts, or haram intercourse; and any other good 
intention." 
4. Tahdhib al'Asma' li-Nawawi, 
1/173. Abu Ishaq ash-Shirazi once entered the mosque to have something to eat, 
as was his custom, and then realised that he had dropped a dinar. He retraced 
his steps and found it lying on the ground, but then left it where it was, 
saying, "Perhaps it is not mine; perhaps it belongs to somebody else." 
5. Sahih, Ja'mi 'l-'Ulum 
wa'l-Hikam, p. 19. 
6. Al-Bukhari and Muslim. 
7. Muslim, 21/17. 
8. Muslim, Kitab at-Tahara, 3/99.