A man’s fulfilling his sexual desire with his wife may often happen as the result of stimulation, by looking or touching etc. Hence fulfilling his desire when it is provoked in such situations is a means of keeping himself chaste and lowering his gaze [from looking at other women].
This is what the Prophet (peace and blessings of Allaah be upon him) taught us to do, according to the hadeeth narrated by Muslim (1403) from Jaabir, who says that the Messenger of Allaah (peace and blessings of Allaah be upon him) saw a woman and he came to his wife Zaynab, whilst she was tanning a skin and preparing it for dyeing, and he fulfilled his need. Then he went out to his companions and said: “Woman comes and goes in the shape of a devil [i.e., she causes temptation], so if any one of you sees a woman, let him go and have intercourse with his wife, for that will take away what he feels in his heart.”
This was also narrated by Ahmad, 19403; Ibn Maajah, 1853.
Ibn Hibbaan narrated in his Saheeh, 4171, that ‘Abd-Allaah ibn Abi Awfa said: “The Messenger of Allaah (peace and blessings of Allaah be upon him) said: ‘No woman fulfils all her duties towards Allaah until she fulfils all her duties towards her husband. If he asks her [for his conjugal rights] even when she is on the back of a camel, she should respond to him.’”