When should the worshipper say the opening Takbir (Takbirat al-Ihram)?
Chapter on the Description of Prayer
Al-Mughni
Book of Prayer
Primary text
The opening Takbir should not be said until the caller has finished the entire Iqamah. This is the position of Al-Hasan, Yahya ibn Waththab, Ishaq, Abu Yusuf, Shafi'i, and the majority of Imams in the major cities. This is because the Prophet (peace be upon him) was known to perform his actions after the Iqamah concluded, specifically correcting the rows and addressing the congregation, as indicated by narrations detailing his actions after the call to establish prayer.
Supporting text
A dissenting view, held by the companions of 'Abdullah (ibn Mas'ud) and others, suggests saying the Takbir immediately upon hearing 'Qad qamat is-salah,' arguing that Bilal's statement about not saying 'Amin' prematurely implies the Takbir occurred before the end of the Iqamah.