Sahih Bukhari Volume 2, Book 23, Hadith 1286

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مُحَمَّدٍ، حَدَّثَنَا أَبُو عَامِرٍ، حَدَّثَنَا فُلَيْحُ بْنُ سُلَيْمَانَ، عَنْ هِلاَلِ بْنِ عَلِيٍّ، عَنْ أَنَسِ بْنِ مَالِكٍ ـ رضى الله عنه ـ قَالَ شَهِدْنَا بِنْتًا لِرَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ وَرَسُولُ اللَّهِ صلى الله عليه وسلم جَالِسٌ عَلَى الْقَبْرِ ـ قَالَ فَرَأَيْتُ عَيْنَيْهِ تَدْمَعَانِ قَالَ ـ فَقَالَ ‏"‏ هَلْ مِنْكُمْ رَجُلٌ لَمْ يُقَارِفِ اللَّيْلَةَ ‏"‏‏.‏ فَقَالَ أَبُو طَلْحَةَ أَنَا‏.‏ قَالَ ‏"‏ فَانْزِلْ ‏"‏‏.‏ قَالَ فَنَزَلَ فِي قَبْرِهَا‏

Narrated By Anas bin Malik : We were (in the funeral procession) of one of the daughters of the Prophet and he was sitting by the side of the grave. I saw his eyes shedding tears. He said, "Is there anyone among you who did not have sexual relations with his wife last night?" Abu Talha replied in the affirmative. And so the Prophet told him to get down in the grave. And so he got down in her grave.