However, a spring or a cistern which collects water will be clean, but one who touches their carcass will be unclean.

but if water is put on the seed and such a carcass falls on it, it is unclean to you.

The priest will then command that one bird be slaughtered into a clay vessel over fresh water.

and he is to slaughter one bird into a clay vessel over fresh water.

Any food that may be eaten which becomes soaked with water will become unclean. Anything drinkable in any such vessel will become unclean.