(4) باب لاَ يَسُبُّ الرَّجُلُ وَالِدَيْهِ
Narrated `Abdullah bin `Amr:
Allah's Messenger (ﷺ) said. "It is one of the greatest sins that a man should curse his parents." It was asked (by the people), "O Allah's Messenger (ﷺ)! How does a man curse his parents?" The Prophet (ﷺ) said, "'The man abuses the father of another man and the latter abuses the father of the former and abuses his mother."
Reference: Sahih al-Bukhari 5973
In-book reference: Book 78, Hadith 4
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 8, Book 73, Hadith 4