Sahih Muslim , Book 4, Hadith 2062 (USC-MSA) ⓘ
Abu Huraira reported Allah's Messenger as saying: He who attends the funeral till the prayer is offered for (the dead), for him is the reward of one qirat, and he who attends (and stays) till he is buried, for him is the reward of two qirats. It was said: What are the qirats? He said: They are equivalent to two huge mountains. Two other narrators added: Ibn 'Umar used to pray and then depart (without waiting for the burial of the dead). When the tradition of Abu Huraira reached him, he said:" We have lost many qirats."
وَحَدَّثَنِي أَبُو الطَّاهِرِ، وَحَرْمَلَةُ بْنُ يَحْيَى، وَهَارُونُ بْنُ سَعِيدٍ الأَيْلِيُّ، - وَاللَّفْظُ لِهَارُونَ وَحَرْمَلَةَ - قَالَ هَارُونُ حَدَّثَنَا وَقَالَ الآخَرَانِ أَخْبَرَنَا ابْنُ وَهْبٍ أَخْبَرَنِي يُونُسُ عَنِ ابْنِ شِهَابٍ قَالَ حَدَّثَنِي عَبْدُ الرَّحْمَنِ بْنُ هُرْمُزَ الأَعْرَجُ أَنَّ أَبَا هُرَيْرَةَ قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ شَهِدَ الْجَنَازَةَ حَتَّى يُصَلَّى عَلَيْهَا فَلَهُ قِيرَاطٌ وَمَنْ شَهِدَهَا حَتَّى تُدْفَنَ فَلَهُ قِيرَاطَانِ " . قِيلَ وَمَا الْقِيرَاطَانِ قَالَ " مِثْلُ الْجَبَلَيْنِ الْعَظِيمَيْنِ " . انْتَهَى حَدِيثُ أَبِي الطَّاهِرِ وَزَادَ الآخَرَانِ قَالَ ابْنُ شِهَابٍ قَالَ سَالِمُ بْنُ عَبْدِ اللَّهِ بْنِ عُمَرَ وَكَانَ ابْنُ عُمَرَ يُصَلِّي عَلَيْهَا ثُمَّ يَنْصَرِفُ فَلَمَّا بَلَغَهُ حَدِيثُ أَبِي هُرَيْرَةَ قَالَ لَقَدْ ضَيَّعْنَا قَرَارِيطَ كَثِيرَةً .
also referenced under: Book 11, Hadith 67 (In-Book) & Hadith 945 (Reference)