Charles Ellicott Commentary Leviticus 11:33

"And every earthen vessel, whereinto any of them falleth, whatsoever is in it shall be unclean, and it ye shall break." — Leviticus 11:33 (ASV)

And every earthen vessel. —The case, however, is different with regard to vessels made of clay and burned in the kiln.

Whereinto any of them falleth. —Better, into which anything of them falls, that is, into which any of the aforesaid portion of a defiling carcass falls . While defiled vessels of other materials were made clean by water, earthen vessels, when they became defiled, had to be destroyed , and their contents were rendered polluted.