Ohalos 11:8-9

Ohalos 11:8

Let’s say that there was a cistern (containing corpse impurity) in a house with a candlestick in it; the candle-holder protrudes above the cistern and a large basket was placed in such a way that if the candlestick were removed, the basket would remain on the mouth of the cistern. In such a case, Beis Shammai say that the cistern remains clean but the candlestick is rendered unclean. Beis Hillel says that the candlestick also remains clean but they concede that if removing the candlestick would cause the basket to fall into the cistern, then everything would be rendered unclean.

Ohalos 11:9

Utensils between the rims of the basket and those of the cistern remain clean all the way down to the depths. If there’s impurity there (in or around the cistern), the house is rendered unclean. If there is impurity in the house, utensils in the walls of the cistern remain clean so long as the place where they are has a space of a cubic handbreadth; if this is not the case, they are rendered unclean. If the walls of the cistern are wider than those of the house, then the utensils remain clean in either event.