Sunan an Nasai 580
The Book of the Times (of Prayer)
أَخْبَرَنَا 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
Grading: Abu Ghuddah: Hasan Sahih · Al-Albani: Hasan Sahih · Zubair Ali Zai: Isnaad Sahih
Text from the public-domain hadith-api dataset. Numbering follows that dataset and can differ by a few from some printed editions — check the wording, not only the number.