'Abdullah bin 'Amr bin Al-'as (May Allah be pleased with them) reported:
Messenger of Allah ﷺ said, "It is one of the gravest sins to abuse one's parents." It was asked (by the people): "O Messenger of Allah, can a man abuse his own parents?" Messenger of Allah ﷺ said, "He abuses the father of somebody who, in return, abuses the former's father; he then abuses the mother of somebody who, in return, abuses his mother".

[Al-Bukhari and Muslim].

Another narration is: Messenger of Allah ﷺ said, "One of the major sins is to curse one's parents". It was submitted: "O Messenger of Allah! How can a man curse his own parents?" He ﷺ said, "When someone curses the parents of another man who in return abuses the former's father; and when someone abuses the mother of another man who in return abuses his mother."

وعنه أن رسول الله ﷺ قال: "من الكبائر شتم الرجل والديه!" قالوا: يا رسول الله وهل يشتم الرجل والديه؟ ! قال: "نعم؛ يسب أبا الرجل، فيسب أباه، ويسب أمه، فيسب أمه" ((متفق عليه)) . وفي رواية "إن من أكبر الكبائر أن يلعن الرجل والديه!" قيل : يا رسول الله كيف يلعن الرجل والديه؟ ! قال "يسب أبا الرجل ، فيسب أباه، ويسب أمه، فيسب أمه".