Sunan an-Nasa'i 1853
سنن النسائي#1853Sahihأَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ حَدَّثَنَا يَحْيَى، قَالَ حَدَّثَنَا شُعْبَةُ، قَالَ حَدَّثَنَا قَتَادَةُ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنِ ابْنِ عُمَرَ، عَنْ عُمَرَ، قَالَ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " الْمَيِّتُ يُعَذَّبُ فِي قَبْرِهِ بِالنِّيَاحَةِ عَلَيْهِ " .
It was narrated that 'Umar said:"I heard the Messenger of Allah say: 'The deceased is punished in his grave due to the wailing over him
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih - Agreed Upon
In-book reference: 21:36