Al-Matalib al-'Aliyah 4604 — The description of Paradise

It is narrated from al-Haytham al-Ta'i and Sulaym bin Amir that the Prophet (peace and blessings be upon him) was asked about marital relations and sexual union in Paradise, and he (peace and blessings be upon him) said: "Yes, there will be a most desirable and delightful repose there, and such manly vigour will be granted in which there will never be weariness or weakness. And indeed a man of Paradise will remain reclining on his couch there for a period equal to forty years, neither moving from it nor feeling any tedium or boredom, and in this very state everything his soul desires and that delights his eyes will be provided to him."
Imam al-Harith bin Abi Usamah recorded this hadith in his Musnad (Bughyat al-Bahith: 1113); because of a break in its chain this narration is mursal, and because of scholarly criticism of some of its narrators it has been declared weak; however, there are other reliable supporting reports about the delights of Paradise.