'Containing' in the Bible

A spring or cistern containing water will remain clean, but someone who touches a carcass in it will become unclean.

in woven or knitted material, in leather, or with any article containing leather,

if the contagion is greenish or reddish in the clothing, leather, woven material, knitted material, or with any article containing leather, it's a fungal infection and is to be shown to the priest.

and he is to slaughter one of the birds over a clay pot containing fresh water.

"You are not to eat anything containing blood, engage in occult practices, or practice fortune telling.