Sunan an-Nasa'i 580
سنن النسائي#580Sahihأَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ أَنْبَأَنَا وَكِيعٌ، قَالَ حَدَّثَنَا طَلْحَةُ بْنُ يَحْيَى، عَنْ عُبَيْدِ اللَّهِ بْنِ عَبْدِ اللَّهِ بْنِ عُتْبَةَ، عَنْ أُمِّ سَلَمَةَ، قَالَتْ شُغِلَ رَسُولُ اللَّهِ صلى الله عليه وسلم عَنِ الرَّكْعَتَيْنِ قَبْلَ الْعَصْرِ فَصَلاَّهُمَا بَعْدَ الْعَصْرِ .
It was narrated that Umm Salamah said:"The Messenger of Allah (ﷺ) got distracted and did not pray the two Rak'ahs before 'Asr so he prayed them after 'Asr
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 GhuddahHasan Sahih
Al-AlbaniHasan Sahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 6:87