Hadith: It is one of the major sins when a man abuses his parents. It was asked: Would a man ever abuse his parents? He replied: Yes. He abuses the father of another man, who in return abuses his father, and he abuses his mother, and so the latter abuses the former’s mother

عن عبد الله بن عمرو بن العاص رضي الله عنهما أن رسول الله صلى الله عليه وسلم قال: «من الكبائر شَتْمُ الرجل والديه» قيل: وهل يسبّ الرجل والديه؟ قال: «نعم، يسبّ أبا الرجل فيسبّ أباه، ويسبّ أمّه، فيسبّ أمّه».
[صحيح] - [متفق عليه]

‘Abdullāh ibn ‘Amr ibn al-‘Ās (may Allah be pleased with him) reported: The Messenger of Allah (may Allah’s peace and blessings be upon him) said: "It is one of the major sins when a man abuses his parents." It was asked: "Would a man ever abuse his parents?" He replied: "Yes. He abuses the father of another man, who in return abuses his father, and he abuses his mother, and so the latter abuses the former’s mother."
[Authentic hadith] - [Narrated by Bukhari & Muslim]

Explanation

This Hadīth points out the great rights and status enjoyed by one’s parents, and it informs that it is a major sin to cause them to be offended or abused by others. If this is the case, then it is far more reprehensible for a person to directly abuse his own parents by himself. When the Prophet (may Allah's peace and blessings be upon him) stated that cursing one’s parents is a major sin, the attendees were quite surprised to hear that, presuming that a man would never do so. Thereupon, the Prophet (may Allah's peace and blessings be upon him) explained to them that this could happen indirectly by causing others to revile one’s parents; when a person curses the father and mother of someone else, and the latter responds in kind.