Abu Huraira reported God’s Messenger as saying, “When one of you leads the people in prayer he should be brief, for among them are the sick, the weak, and the aged. But when one of you prays by himself he may be as long as he likes.” (Bukhari and Muslim.)
Hadith Referenceمشكوة المصابيح / كتاب الصلاة / 1131
Hadith Gradingالألبانی:مُتَّفَقٌ عَلَيْهِ | زبیر علی زئی:متفق عليه
Hadith Takhrij´تحقيق و تخريج: محدث العصر حافظ زبير على زئي رحمه الله` «متفق عليه، رواه البخاري (703) و مسلم (183/ 467)»