Assalaamu alaykum. What are the major and minor sins?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

Listing the major and minor sins is a very long process that belongs to the detailed books written by scholars. Some scholars held that the number of major sins is seventy while others listed a much bigger number. A group of scholars authored books on that particular topic, such as Al-Haytami, Ath-Thahabi, and others. You may refer to Al-Haytami's book Az-Zawaajir ʻan Iqtiraaf Al-Kabaa'ir and Ath-Thahabi's book Al-Kabaa'ir.

Al-Hajjaawi compiled a concise poem in which he listed the grave sins. Late scholars authored some books on major sins such as Al-Kabaa'ir by Muhammad ʻAbd Al-Wahhaab; it is a concise book in which he cited much evidence. A revised edition of the book was issued and the Ahaadeeth cited therein were classified.

It is important to know the criterion in differentiating between major and minor sins. Al-Qurtubi wrote, "A major sin is any sin which Allah mentioned after it Hellfire, wrath, curse, or punishment." [Tafseer Al-Qurtubi]

Shaykh Ibn ʻUthaymeen wrote, "A major sin is that of which the consequence is a specific punishment. In other words, it was not only forbidden or prohibited; rather, a specific punishment was assigned for it. For instance, if it was said (in texts of the Quran and Sunnah): whoever commits such and such a sin is not a Muslim, or not one of us, or the like. The minor sins are whatever was declared prohibited but for which no specific punishment was assigned."

Hence, minor sins are all the misdeeds other than the grave sins, such as small mistakes. Based on this view, the category of minor sins includes an almost uncountable number of misdeeds.

Allah knows best.