Prophet Muhammad followed only what was sent down to him 10:15-16
10:15 When Our verses, clear verses, are recited to them, those who do not reckon to meet Us say, 'Bring a Koran other than this, or make changes in it.' Say, 'It is not for me to change it by myself. I follow nothing, except what is sent down to me. Indeed, if I should rebel against my Lord I fear the punishment of a Great Day.'
10:16 Say (Prophet Muhammad), 'Had Allah willed, I would not have recited it to you, nor would He have made it known to you. I lived among you all my life before it (was sent down). Will you not understand?'