What is the ruling on the prayer of one whose imam paused during recitation and was prompted by the worshippers more than three times in a single bowing (rak'ah), whereupon the imam bowed, then after bowing and prostrating for the first rak'ah, he sat down, so the worshippers prompted him, whereupon he stood and bowed without recitation, then they prompted him again, so he prostrated without recitation, then one of the worshippers gestured to him that there was one rak'ah remaining, so he completed the prayer and performed the prostration of forgetfulness (sujud sahwi) after the salutation, and what are the implications for an imam if he is unable to recite?

If the Imam recites the entire Fatiha in the last رکعه, and his action was due to forgetfulness and not intentional, then his prayer is valid, as is the prayer of those behind him, and he must perform the prostration of forgetfulness (sujud as-sahw) after the salām. The prayer is not invalidated by the aforementioned speech because it is for rectification after the tasbīḥ (glorification) which did not achieve its purpose. The original principle is that for one who experiences something [unexpected] in his prayer, tasbīḥ is prescribed. If the purpose is not achieved, then speech is prescribed to provide a warning, provided it is not excessive. As for the Imam, if he finds it difficult to recite the Fatiha and prompting (fatḥ) does not help, it is recommended for him to appoint one of the congregants as his successor. If he finds it difficult to recite something other than the Fatiha, then it is not prescribed for him to appoint a successor; rather, he should recite a verse with the Fatiha and complete his prayer.