Mishkat al-Masabih 1715
Anas said:
I was present when the daughter of God’s messenger was being buried. He was sitting beside the grave and I saw his eyes shedding tears. He then asked, “Is there any of you who did not have sexual intercourse last night?” Abu Talha replied that he had not, so he told him to go down into her grave, and he did so. 

Bukhari transmitted it.
عَنْ أَنَسٍ قَالَ: شَهِدْنَا بِنْتَ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ تُدْفَنُ وَرَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ جَالِسٌ عَلَى الْقَبْرِ فَرَأَيْتُ عَيْنَيْهِ تَدْمَعَانِ فَقَالَ: 
" هَلْ فِيكُمْ مَنْ أَحَدٍ لَمْ يُقَارِفِ اللَّيْلَةَ؟ . فَقَالَ أَبُو طَلْحَةَ: أَنَا. قَالَ: فَانْزِلْ فِي قَبْرِهَا فَنَزَلَ فِي قبرها ". رَوَاهُ البُخَارِيّ