Was Jesus in error when he spoke about salt losing its salinity?
In his Sermon on the Mount, Jesus told his followers: “You are the salt of the earth; but if the salt loses its strength, how will its saltness be restored? It is no longer usable for anything but to be thrown outside to be trampled on by men.” (Matthew 5:13) Salt is a preservative. Hence, Jesus’ illustration likely meant that his disciples could and should protect others from spiritual and moral decay.
With regard to Jesus’ comment about salt losing its salinity, however, The International Standard Bible Encyclopedia says: “The salt from the Dead Sea region was generally contaminated with other minerals; thus the salt could be dissolved out of this mixture, leaving a tasteless substance.” It is understandable, therefore, that Jesus described the residue as “no longer usable for anything but to be thrown outside.” “Although its impurity made the salt from the Dead Sea inferior to most sea salts,” the encyclopedia adds, “its accessibility (it could simply be picked up along the shore) made it the main source of salt for Palestine.”
What meaning would the loss of a drachma coin in Jesus’ parable have to his listeners?
Jesus told the parable of a woman who after losing one of the ten drachmas she possessed took a lamp and swept her house carefully until she found it again. (Luke 15:8-10) In Jesus’ day, a drachma was worth almost a day’s wage, so the monetary loss Jesus illustrated was not trivial. Yet, the scene he described was true to life for other reasons.
Some reference works indicate that women often used coins as ornaments. Jesus may thus have alluded to a coin that was part of a cherished heirloom or part of a woman’s dowry. Whether this was the case or not, losing one of her ten coins would understandably make the woman extremely anxious to recover it.
The houses of common people in Jesus’ day, moreover, were designed to keep out as much light and heat as possible. They had few, if any, windows. The floors were usually covered with straw or dried stems of various plants. If a coin was dropped, it would be hard to find. “Hence,” says one commentator, “when a comparatively small article, like a piece of money, was lost in such a place, the lighting of a lamp, and the sweeping of the house, were the most natural means to be used for its recovery.”