Alerting the ma'mum to the imam by means other than tasbih

Question:
Our friend the Shaykh, is it permissible for the ma'mum to speak words to alert the imam that he has made a mistake in the tasbih, if the imam has not led the prayer correctly in some way?

Answer:
He says, "Subhan Allah," and he recites the tasbih. The scholars of knowledge said that if a verse comes that serves as an alert, there is no harm. If he finds a verse that indicates an alert, he recites it for that purpose to alert the imam, just as if he forgot the ruku' and the imam recited . He must be alerted that he forgot the ruku' or forgot the sujud. The ma'mum said, "Sujud and come closer," so the imam would remember that he had forgotten the sujud, and there is no harm. So, if a verse comes that alerts to forgetfulness, there is no harm. As for ordinary speech, no. The Messenger (peace and blessings be upon him) said that the men reciting tasbih is sufficient.