It is narrated from Sayyiduna Mu'awiyah bin Abi Sufyan (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) used to say: "O people, do not race ahead of me in bowing and prostration. However much I precede you, when I bow you will catch up with me when I rise. Indeed, I have grown heavy with age."
That is: I have become old. These are the words of the narration of Sulayman bin Bilal.
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 16911