Kitab al-Kafi
Stoning is described as punishment in multiple hadiths. Shia and Sunni hadith collections differ because scholars from the two traditions differ as to the reliability of the narrators and transmitters and the Imamah. Shi'a sayings related to stoning can be found in Kitab al-Kafi, and Sunni sayings related to stoning can be found in the Sahih Bukhari and Sahih Muslim. Based on these hadiths, in some Muslim countries, married adulterers are sentenced to death, while consensual sex between unmarried people results in 100 lashes.