One of the most difficult topics in the study of ritual purity is that of the corpse in the ‘tent’, and particularly the question of how the biblical law expressed so briefly in Numbers 19:14–16 proliferated into the complex system found in Mishnah Ohalot and elsewhere.

Numbers says simply: ‘When a man dies in a tent, this is the law: everyone who goes into the tent and everyone who was inside the tent shall be ritually unclean for seven days, and every open vessel which has no covering tied over it shall also be unclean. In the open, anyone who touches a man killed with a weapon or one who had died naturally, or who touches a human bone or a grave, shall be unclean for seven days’ (NEB).

These verses differentiate between a corpse that is enclosed in a ‘tent’ and a corpse that is in the open. When it is enclosed, it transmits impurity even to those people and vessels that have not touched it; simply to be under the same roof as the corpse is sufficient to incur impurity. In the open, however, a corpse (or even part of a corpse) transmits impurity by touch only. A grave, on the other hand, has its own individual impurity, by which it transmits impurity by touch in the open, even if the corpse itself is not touched.

Rabbinic law fills out this account in certain commonsense ways that are not problematic.