ENOfficial
It was narrated that 'Abdullah bin Al-Mughaffal said: "The Messenger of Allah (ﷺ) said: 'Whoever follows a Janazah until it is finished, he will have two Qirats, and whoever goes back before it is finished, he will have one Qirat."
Source: sunnah.com
Other translations
Arabic
أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ الأَعْلَى، قَالَ حَدَّثَنَا خَالِدٌ، قَالَ حَدَّثَنَا أَشْعَثُ، عَنِ الْحَسَنِ، عَنْ عَبْدِ اللَّهِ بْنِ الْمُغَفَّلِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ تَبِعَ جَنَازَةً حَتَّى يُفْرَغَ مِنْهَا فَلَهُ قِيرَاطَانِ فَإِنْ رَجَعَ قَبْلَ أَنْ يُفْرَغَ مِنْهَا فَلَهُ قِيرَاطٌ " .
sunnah.com