The Prophet's ﷺ hair did not extend beyond his earlobes.
حدثنا عفان حدثنا حماد بن سلمة أخبرنا حميد
كان النبي ﷺ لا يجاوز شعره شحمة أذنيه
No references are available.
Its isnad is sahih, mentioned previously at 12385.