From Sahih Bukhari (Hadith 1323):
Narrated Nafi`:Ibn `Umar was told that Abu Huraira said, "Whoever accompanies the funeral procession will have a reward equal to one Qirat." Ibn `Umar said, "Abu Huraira talks of a too enormous reward." Aisha attested Abu Huraira's narration and said, "I heard Allah's Messenger (ﷺ) saying like that." Ibn `Umar said, "We have lost numerous Qirats
Reference: Bukhari 1323