Page "Isma'il ibn Jafar" Paragraph 4

According to the majority of the available sources, Imam Ja ’ far al-Sadiq had indeed designated Ismail by nass ( divine decree ) as his successor in Imamate.

After the death of Imam Ja ’ far al-Sadiq a great confusion arose amongst his sons as each of his surviving sons claimed the Imamat but could not produce sufficient credentials, and so their followers melted away in a short period expect for two candidates ; Ismail and Musa.

Ultimately the majority of the Shia favoured Musa al-Kazim, a younger son of Imam Ja ’ far al-Sadiq and half-brother of Ismail.

The Twelver Shia, however, believe that Imam Ja ’ far al-Sadiq revoked his first nass in favour of Ismail and made a second nass in favour of his son Musa al-Kazim.