وَعَنْ عُثْمَانَ رضى الله عنه
قَالَ: «كَانَ رَسُولُ اَللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: إِذَا فَرَغَ مِنْ دَفْنِ الْمَيِّتِ وَقَفَ عَلَيْهِ وَقَالَ: «اِسْتَغْفِرُوا لِأَخِيكُمْ وَسَلُوا لَهُ التَّثْبِيتَ، فَإِنَّهُ الْآنَ يُسْأَلُ»
Uthman Ibn Affan (RAA) narrated, ‘Whenever the Messenger of Allah (sallallahu alayhi wa sallam) finished the burial of the dead, he would stand by the grave and say, ‘Seek forgiveness for your brother and pray for him to be steadfast, because he is now being questioned.’ Related by Abu Dawud. Al-Hakim graded it as Sahih.’
Bulugh al-Maram 690, Book 3, Funerals, Hadith 50. 1 min read