Sahih Muslim, 6062

Ibn Abbas reported that the People of the Book used to let their hair fall (on their foreheads) and the polytheists used to part them on their heads, and Allah's Messenger (ﷺ) liked to conform his behaviour to the People of the Book in matters in which he received no command (from God) ; so Allah's Messenger (ﷺ) let fall his hair upon his forehead, and then he began to part it after this

Rapporté par Ibn Abbas رضي الله عنه : Les Gens du Livre laissaient leurs cheveux retomber sur leur front, tandis que les polythéistes les séparaient au milieu. Le Messager d’Allah ﷺ aimait se conformer aux Gens du Livre dans les domaines où il n’avait pas reçu de commandement. Il a donc laissé ses cheveux tomber sur son front, puis il a commencé à les séparer par la suite