Musannaf Ibn Abi Shayba 6:826

11625. Abdullah bin Numayr narrated to us, from Muhammad bin Ishaq, from Yazid bin Abi Habib, from Marthad bin Abdullah al-Yazani, from Malik bin Hubayrah al-Shami—and he had companionship [with the Prophet]—who said: When he would come to a funeral, he would divide those with it into three rows, then he would pray over it. And he said: "Indeed, the Messenger of Allah (ﷺ) said: 'No three rows of Muslims stand over a dead person except that it becomes obligatory [for them to be forgiven].'"