The Messenger of Allah ﷺ said, "When one of you leads the prayer, let him keep it brief, for behind him stand the weak, the elderly, and those with pressing needs. But when he prays alone, let him prolong it as much as he wishes."
حدثنا يزيد أخبرنا محمد عن أبي سلمة
قال رسول الله ﷺ إذا كان أحدكم إماما فليخفف فإنه يقوم وراءه الضعيف والكبير وذو الحاجة وإذا صلى لنفسه فليطول ما شاء