“Unclean for seven days by a dead body”
Whoever touches any dead body will be unclean for seven days. (Numbers 19:11 BSB)
What it sounds like today
A superstitious-sounding rule about touching corpses.
The cultural key
Contact with a human corpse was regarded as the most severe form of ritual impurity, lasting a full seven days and requiring the special 'water of purification' made from the ashes of the red heifer to remove. The logic is the recurring one: death is the ultimate opposite of the living, holy God, so a body, the very embodiment of death, radiated the strongest defilement, and anyone or anything it touched became unclean and had to be purified before approaching the sanctuary. This law is essential background to a famous Gospel scene: in the parable of the Good Samaritan, a priest and a Levite see a man lying 'half dead' and pass by on the other side, in part because touching what might be a corpse would render them ritually unclean and unable to perform their temple duties; they choose ceremonial purity over compassion. Jesus's point cuts against exactly this reasoning. A modern reader sees an odd taboo; the first hearers understood the weight of corpse-impurity, and how it could be used as an excuse.
Recovered meaning
A corpse was the strongest source of ritual impurity, defiling for seven days, because death is the opposite of the holy God. This is the background to the Good Samaritan, where the priest and Levite avoid the 'half dead' man rather than risk corpse-impurity.