Al-Husayn ibn Sa’id from Safwan from Ibn Bukayr from ‘Ubayd ibn Zurarah, who said: I asked Abu Abdillah عليه السلام about a man who gave the ‘Iqamah’ for prayer but forgot to say the Takbirat al-Ihram (opening Takbir) and began the prayer. Imam عليه السلام said: "He must repeat it."