Kitāb al-Ghayba

Hadith 397
occultationguidance-misguidance
193- وقد روي أنه لما ولد لأبي الحسن عليه السلام جعفر هنئوه به فلم يروا به سرورا، فقيل له في ذلك فقال: هون عليك أمره سيضل خلقا كثيرا.
H 193 - It is narrated that when Ja’far was born to Abul Hasan (a.s), people congratulated him, but they did not see any signs of joy in him. He was asked about it. The Imam replied, “Take his birth easy; he will misguide many.”
Source: Shaykh Muḥammad b. al-Ḥasan al-Ṭūsī