Description and usage
The clay jar was an earthenware vessel that was used as a storage container for liquids like wine and olive oil (see also Containers for storage). It could also be used to carry water and other liquids.
Translation
Unlike stone water jars (see Stone jar), which were intended only for the storage of water, clay jars had to be light enough when full to be carried by a woman, who normally did such work in the society of that time. While John uses the same Greek word for “jar” in 2.6 and in 4.28, it is clear from the context that two different kinds of vessels are intended. The woman in JHN 4:28 would not have been carrying a stone jar, which would have been very heavy. Most translations have “water jar” (RSV, GNT). Where a language makes a distinction between a vessel for drawing or carrying water and a vessel for drinking, a word for the former vessel should be used.