Hadithcore
Sahih Muslim, 3022 a
sahih

'Urwa reported on the authority of his father that 'A'isha said to him:

O, the son of my sister, the Muslims were commanded to seek forgiveness for the Companions of Allah's Messenger (ﷺ) but they reviled them.

حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، أَخْبَرَنَا أَبُو مُعَاوِيَةَ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ أَبِيهِ، قَالَ قَالَتْ لِي عَائِشَةُ يَا ابْنَ أُخْتِي أُمِرُوا أَنْ يَسْتَغْفِرُوا، لأَصْحَابِ النَّبِيِّ صلى الله عليه وسلم فَسَبُّوهُمْ ‏.‏

References2 variants
In-Book Reference
Book 56, Hadith 17
USC-MSA web (English) reference
Book 43, Hadith 7167 (deprecated numbering scheme)