What is the ruling on praying behind imams who add a "waw" to the takbirat al-ihram, saying "Allah wa-Akbar"?

The prescribed formula for entering into prayer is "Allahu Akbar" (Allah is the Greatest). The prayer does not commence without this utterance, according to the majority of scholars, who cite the Prophet's (peace be upon him) sayings: "(Its prohibition is the Takbir)" and "(When you stand for prayer, say Takbir)."

Changing this formula by adding a waw between the two words, such as "Allahu wa Akbar," distorts and corrupts the meaning. Therefore, many scholars have explicitly stated that the prayer does not commence with this alteration.

Al-Nawawi said: "One must be careful in the Takbir not to pause between its two words, nor to add anything that changes the meaning. If one pauses, or says 'Aallahu Akbar' by elongating the hamza of Allah, or with two hamzas, or says 'Allahu Akbaar,' or adds a silent or voiced waw between the two words, his Takbir is invalid."

Ibn Qasim said: "It is not valid if he reverses it... or adds a silent or voiced waw between the two words."

Some Maliki scholars disagreed, stating that the prayer does commence with the phrase "Allahu wa Akbar." However, Al-Adawi rebutted this, saying that it is an individual interpretation of its proponent and not what the Maliki school of thought holds.

The preponderant view is that the prayer does not commence except with the formula of Takbir transmitted from the Prophet (peace be upon him): "Allahu Akbar."

It is necessary to advise the Imam and explain the rulings of the scholars on this matter. If he responds, then that is well and good. If he does not respond, then look for another Imam who establishes his prayer correctly.