And a pure man shall gather the ashes of the heifer and place them outside the camp in a pure place; and it shall be for the congregation of the children of Yisrael for a keeping, for water of sprinkling; it is a chatas.
Torah Temimah: Yoma 43a — “And he shall place” — one who has the mental capacity to set aside; this excludes a deaf-mute, an imbecile, and a minor, who lack the mental capacity to set aside.
English: One who has the mental capacity to set aside; this excludes a deaf-mute, an imbecile, and a minor, who lack the mental capacity to set aside.
Requirement of daas for the act of setting the ashes aside.
The person who gathers and places the ashes must possess normal adult mental capacity; a cheresh, shoteh, or katan is disqualified from this role.