What is the ruling when a follower joins the Imam between the two Takbeers (of the opening sequence)?
General Chapter
Al-Mughni
Book of Funerals
Primary text
If the follower perceives the Imam between the two opening Takbeers, the ruling is that the follower waits for the Imam to perform the next Takbeer with him. This view is held by Ahmad, Abu Hanifa, Al-Thawri, and Ishaq. The reasoning is that the Takbeers are analogous to the Rak'ahs; if one misses a Rak'ah, one does not preoccupy oneself with immediately making it up, similarly if one misses a single Takbeer.
Supporting text
The second opinion states that the follower should proceed with the Takbeer and not wait. This is the view of Al-Shafi'i, based on the principle that in all other parts of the prayer, when one joins the Imam, one proceeds without waiting, and this is not considered making up what was missed, but rather praying with the Imam what is attained.