In what sort of vessel does the Kohen mix the water and the ashes?
Targum Yonasan: In an earthenware vessel.
What is the exact procedure regarding the ashes and the water?
Ramban: The Kohen first pours the spring-water into the earthenware vessel; 1 and what the Pasuk means is that he mixes them until the water is floating on top of the ashes.
Ramban: In spite of the implications to the contrary (See Ramban).
Why does the Torah write "me'Afar" spelt with an 'Ayin'?
Rashi (in Ta'anis, 15a): The Torah sometimes calls 'Eifer', 'Afar'.