Sayyiduna Uthman bin Abi al-As (may Allah be pleased with him) said: The last advice the Messenger of Allah (peace and blessings be upon him) gave me was: "When you lead your companions in prayer, lead them according to the weakest of them, for among them are the weak and the sick."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 8348