Sunan Ibn Majah
1541
Sahih+3

It was narrated from Ubayy bin Ka’b that the Messenger of Allah (ﷺ) said:‘Whoever offers the funeral prayer will have one Qirat; and whoever attends until the burial is over, will have two Qirat. By the One in Whose Hand is the soul of Muhammad! The Qirat is greater than this (mountain of) Uhud.”

SahihAl-Albani
SahihMuhammad Fouad Abd al-Baqi