Sayyed Mohammad Al-Musawi, Sayyed Mohammad al-Musawi is originally from Iraq and heads up the World Ahlul Bayt Islamic League in London. Other than being involved in various humanitarian projects, he frequently responds to... Answered 7 months ago

Allah (SWT) appointed all the prophets and all their successors. Prophet Muhammad (SAWA) informed about the names of his twelve successors (AS). Jaabir ibn Abdullah al-Ansaari, the pious companion of the Prophet Muhammad (SAWA) was among those who were been informed about the names of the twelve Imams after the Prophet (SAWA). 

 Infallible Imam informs some of his most trusted followers about the Imam after him, and that also depends on the situation. Appointment is from Allah (SWT) and informing is from the Imam (AS) about his successor.