It is narrated from Sayyiduna Jabir (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "When you lead the prayer, keep it brief, for behind you are the weak, the elderly, the sick and those who have needs."
Hadith Referenceالمعجم الأوسط / باب العين / 3732
Hadith Takhrij«أخرجه أبو يعلى فى «مسنده» برقم: 1795، 1798»