The Messenger of Allah ﷺ said, "Whoever follows a funeral procession until the prayer is performed over the deceased earns one qirat of reward."The Messenger of Allah ﷺ was asked about the qirat, and he replied, "It is like Mount Uhud."
حدثنا يحيى عن إسماعيل حدثني سالم أبو عبد الله
عن رسول الله ﷺ قال من تبع جنازة حتى يصلي عليها فإن له قيراطا فسئل رسول الله ﷺ عن القيراط فقال مثل أحد
Its isnad is sahih. Ismail is Ibn Abu Khalid. This hadith is definitely among the mursal narrations of the companions, for Abdullah bin Umar only heard it from Abu Hurairah and from Ayesha when she confirmed Abu Hurairah, as passed at 4453. They used to confirm one another, so one of them would narrate what he heard from his brother, trusting him and confirming him.