Joshua 10:39

And he took it, and the king thereof, and all the cities thereof; and they smote them with the edge of the sword, and utterly destroyed all the souls that were therein; he left none remaining: as he had done to Hebron, so he did to Debir, and to the king thereof; as he had done also to Libnah, and to her king.

The verse records that Joshua took Debir with its king and its towns and struck down every person there with the sword, leaving no one alive, just as had been done to Hebron and to Libnah. This belongs to the account of Israel's conquest of the small kingdoms of Canaan under Joshua, when the victories were gained with the Captain of Jehovah's hosts present. The souls destroyed are the people themselves, the whole living person and entire being, not a separate inner entity placed in man that lives on after death. A soul in this sense is therefore mortal and can be slain, killed, and utterly destroyed by the sword, and the soul is never described as immortal, deathless, or undying.

Conquest Setting and Lessons

The taking of Debir, its king, and all its cities belongs to the record of Israel's battles and conquest of several small kingdoms in Canaan, forming part of Joshua's greatest work begun when about eighty years old, leading Israel to conquer foes, divide the land, and find the promised rest.
Those victories were gained with the Captain of Jehovah's hosts present, as when the invisible army of God leveled the walls of Jericho, the first-fruit of that evil land.
This stands opposite the defeat at Ai, which came when Israel failed to trust.

The peoples were not spared because continuing to live and multiply would have perpetuated the same corrupt way of life.
The record shows how soon Israel might have possessed all the land had they been faithful.
General backsliding after Jericho brought repeated captivity, so Israel lived in adversity through the years she might have lived in prosperity.

Soul Means Person

In this account the souls destroyed are the people themselves who lived in the cities, the whole living person and whole being, the entire man or person who was put to death with the sword. The word does not here denote a separate immortal entity or inner man put inside man that leaves the body at death. The slaying of all the souls in Debir, as had been done at Hebron and Libnah, was the killing of all the persons in the cities, with none left remaining. The verse uses the word over and over in that sense to count the people destroyed.

The primary meaning of soul is the whole being, the whole creature, a living person. In the original language the word is nephesh, elsewhere translated soul, life, person, mind, heart, body, will, appetite and in many other ways but never spirit. The wording for those put to death is dead soul.

Soul has other Bible senses besides person, so no single definition covers every use. One other sense is life or breath which all creatures possess alike and is shared by humans and animals, even the lowest kinds of creatures possessing animal life being called by the same living soul. Another sense is the affections, impulses, energies, and mental powers within, used like heart or mind.

Souls Can Die

At Debir Joshua took the king and all its towns and struck them with the edge of the sword and utterly destroyed all the souls in them and left none remaining, just as he had done to Hebron and to Libnah and her king. The souls there were the people themselves who lived in the cities, the whole persons counted over and over in that conquest, and all those persons were killed when the cities were destroyed. The king of Debir was killed with them and none was left alive, for the word souls names the people whose lives were taken.

A soul in this sense is a living person who can be slain and killed by men and destroyed by the sword. What was destroyed was the inhabitants themselves, showing the whole human person to be mortal. It was not a separate immortal part placed inside man, nor a conscious part surviving the death of the body. In the original the wording for those put to death is dead soul.

A soul can be spoken of as living or dead, and can be lifeless before receiving the breath of life. The soul that sins dies.

Here the word does not mean an immortal or never-dying part of a person. The soul is never described as immortal, deathless, or undying, nor is immortality ever affirmed of it. In Hebrew it is nephesh, elsewhere rendered soul, life, person, mind, heart, body, will, appetite and many other ways but never spirit, and these souls were struck with the sword and wiped out so that none were left, which means a mortal life or person that can be killed and destroyed.