Sahih Muslim | Book 8 | Hadith Number 3302

Narrated by 'Uqba b. Amir (Allah be pleased with him)
'Uqba b. Amir (Allah be pleased with him) reported Allah's Messenger (may peace be upon him) as saying: The most worthy condition which must be fulfilled is that which makes sexual intercourse lawful. In the narration transmitted by Ibn Muthanna (instead of the word "condition") it is "conditions".