(Ibid. 19:10) "and have them wash their garments": Whence is it derived that they (themselves) required immersion? It follows a fortiori, viz.: If where washing of garments is not required (e.g., in an instance of touching a sheretz), immersion is required, how much more so here, where washing of garments is required. There is no washing of garments in the Torah where immersion is not required.