If anyone attends the funeral and prays over (the dead), he will get the reward of one qirat, and if anyone attends the funeral until the completion (of the burial), he will get the reward of two qirats, the smaller of them being equivalent of Uhud, or one of them being equivalent to Uhud.  

مَنْ تَبِعَ جَنَازَةً فَصَلَّى عَلَيْهَا فَلَهُ قِيرَاطٌ وَمَنْ تَبِعَهَا حَتَّى يُفْرَغَ مِنْهَا فَلَهُ قِيرَاطَانِ أَصْغَرُهُمَا مِثْلُ أُحُدٍ أَوْ أَحَدُهُمَا مِثْلُ أُحُدٍ  

'Abd Allah b.'Umar dont you hear what Abu Hurairah says ? He heard the Messenger of Allah ﷺ say: If anyone goes out of his house, accompanies bier and prays over it.... He then mentioned the rest of the tradition as narrated by Sufyan. Thereupon Ibn 'Umar sent someone to 'Aishah (asking her about it). She replied: Abu Hurairah spoke the truth.  

سَمِعَ رَسُولَ اللَّهِ ﷺ يَقُولُ مَنْ خَرَجَ مَعَ جَنَازَةٍ مِنْ بَيْتِهَا وَصَلَّى عَلَيْهَا فَذَكَرَ مَعْنَى حَدِيثِ سُفْيَانَ فَأَرْسَلَ ابْنُ عُمَرَ إِلَى عَائِشَةَ فَقَالَتْ صَدَقَ أَبُو هُرَيْرَةَ  

I heard the Prophet ﷺ say: If any Muslim dies and forty men associate nothing with Allah stand over his bier. Allah will accept them as intercessors for him.  

سَمِعْتُ النَّبِيَّ ﷺ يَقُولُ مَا مِنْ مُسْلِمٍ يَمُوتُ فَيَقُومُ عَلَى جَنَازَتِهِ أَرْبَعُونَ رَجُلاً لاَ يُشْرِكُونَ بِاللَّهِ شَيْئًا إِلاَّ شُفِّعُوا فِيهِ