Offering obligatory Prayer behind an Imam offering a supererogatory Prayer and offering Salah behind a boy

Q 3: Is it permissible for a Muslim intending to perform an obligatory Salah to be led by someone who is performing a Sunnah Ratibah (supererogatory Prayer performed on a regular basis) or other Salah (Prayer)? Please answer this in detail. And what is the ruling on performing Salah behind minors or smokers?

A: The sound scholarly opinion is that there is nothing wrong in performing an obligatory Salah led by someone performing a supererogatory Salah. This is based on the story of Mu‘adh (may Allah be pleased with him) who used to perform Salah with the Prophet (peace be upon him) and then go to lead his people in offering that Salah. There is also nothing wrong in performing Salah behind discerning children, according to the sound scholarly opinion. This is based on the story of `Amr ibn Salamah who used to lead his people in Salah when he was a young boy. There is nothing wrong in performing Salah behind Muslims who smoke or perform other acts of disobedience, according to the sounder scholarly opinion. However, if it is possible to perform Salah behind other people who are upright, that would be better. Smokers and those who commit sins publicly should not be appointed as Imams, because they would be (Part No. 6; Page No. 304) bad examples to others.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.