Mishkat al-Masabih #1663
Funerals
The Arabic includes the chain of narration (sanad) and the collector's commentary; the English translation shows the Prophet's words only.
وَعَنِ الْبُخَارِيِّ تَعْلِيقًا قَالَ: لَمَّا مَاتَ الْحَسَنُ بن الْحسن بن عَليّ ضَرَبَتِ امْرَأَتُهُ الْقُبَّةَ عَلَى قَبْرِهِ سَنَةً ثُمَّ رَفَعَتْ فَسَمِعَتْ صَائِحًا يَقُولُ: أَلَا هَلْ وَجَدُوا مَا فَقَدُوا؟ فَأَجَابَهُ آخَرُ: بَلْ يَئِسُوا فَانْقَلَبُوا
Bukhari said without a full isnad that when al-Hasan b. ‘Ali died, his wife put a tent over his grave for a year; then when she removed it she heard one shouting and saying, “Have they found what they lost?” and another replied, “No, they have given up hope and gone away.”
About Mishkat al-Masabih
This hadith is #1663 from Mishkat al-Masabih, in the Book of Funerals.