Why were some hadiths fabricated after Muhammad’s death?

The fabrication of hadiths after the death of Muhammad occurred for several complex reasons, often driven by the desire to influence the religious and social landscape of the expanding Islamic empire.123

• Establishing Authority: Forgers recognized that attributing a statement to Muhammad granted it immense authority. By creating reports, individuals sought to buttress their personal views, sectarian positions, or legal opinions with the perceived sanction of the Prophet.123
• Accommodating New Situations: As the Muslim community grew and encountered diverse cultures, there was a need to address contemporary issues that were not explicitly covered in earlier traditions. Fabricated hadiths were often used to create a "normative past" that could justify or accommodate these new situations.3
• Pious Intentions: Some forgeries were motivated by what the authors perceived as "pure" intentions. These individuals, desiring to encourage virtues such as piety, charity, or ritual observance, fabricated sayings they believed echoed the spirit of Muhammad’s message. While these were sometimes harder to detect, Hadith scholars denounced them as particularly pernicious.1

To combat these forgeries, scholars developed rigorous verification methods, including the study of the isnad (chain of transmission) and the evaluation of transmitters' reliability.245