Abu Huraira reported: The Messenger of Allah, peace and blessings be upon him, said, “If one of you leads people in prayer, let him lighten it as among them are the weak, sick, and elderly. If one of you prays by himself, let him pray for as long as he wishes.”
Source: Ṣaḥīḥ al-Bukhārī 671
Grade: Sahih (authentic) according to Al-Bukhari
عَنْ أَبِي هُرَيْرَةَ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ إِذَا صَلَّى أَحَدُكُمْ لِلنَّاسِ فَلْيُخَفِّفْ فَإِنَّ مِنْهُمْ الضَّعِيفَ وَالسَّقِيمَ وَالْكَبِيرَ وَإِذَا صَلَّى أَحَدُكُمْ لِنَفْسِهِ فَلْيُطَوِّلْ مَا شَاءَ
671 صحيح البخاري أبواب صلاة الجماعة والإمامة باب إذا صلى لنفسه فليطول ما شاء