Ruling on if Imaam forgets to say: “Sami Allaahu liman hamidah”

Question 501: The Imaam (the one who leads congregational Prayer) forgot to say, “Sami Allaahu liman hamidah (Allaah listens to those who praise Him)” and said instead, “Allaahu Akbar (Allaah is the Greatest).” Should he perform Sujood-ul-Sahw (Prostrations of Forgetfulness)? I am sending you two books that I would like Your Eminence to give your opinion on!

Answer: Tasmee‘ (saying: “Sami‘a Allaahu liman hamidah [Allaah listens to those who praise Him]”),” when standing after Rukoo‘) is one of the obligatory actions of Salaah (Prayer), because the Prophet (peace be upon him) always did it. If an Imaam or someone offering Salaah individually forgets to say it, then it is obligatory on them to perform Sujood-ul-Sahw to make up for what they missed..read more here.