´It was narrated that Abu Musa Al-Ash’ari said:` “The Messenger of Allah (ﷺ) said: ‘When the Imam recites, then listen attentively, and if he is sitting (in the prayer) then the first remembrance that anyone of you recites should be the Tashahhud.’”
Hadith Referenceسنن ابن ماجه / كتاب إقامة الصلاة والسنة / 847
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:صحيح مسلم