The imams after Imam Ali (a.s.) are the children of the Messenger of Allah (s.a.w.).

Imam Musa al-Kadhim (PBUH) taught kindness, honesty, and justice as keys to divine mercy. When Caliph Harun questioned why the Imams were called the Prophet’s progeny, Imam proved through Qur’anic verses—especially about Jesus and the verse of Mubahilah—that descent can be through the mother, affirming Ahl al-Bayt’s lineage from Prophet Muhammad (PBUH&HP).