Flavius Josephus, Antiquities of the Jews
William Whiston, A.M., Ed.

[76] Now Joshua, when he had thus spoken to them, found that the multitude approved of his proposal. So he sent men to measure their country, and sent with them some geometricians, who could not easily fail of knowing the truth, on account of their skill in that art. He also gave them a charge to estimate the measure of that part of the land that was most fruitful, and what was not so good: for such is the nature of the land of Canaan, that one may see large plains, and such as are exceeding fit to produce fruit, which yet, if they were compared to other parts of the country, might be reckoned exceedingly fruitful; yet, if it be compared with the fields about Jericho, and to those that belong to Jerusalem, will appear to be of no account at all; and although it so falls out that these people have but a very little of this sort of land, and that it is, for the main, mountainous also, yet does it not come behind other parts, on account of its exceeding goodness and beauty; for which reason Joshua thought the land for the tribes should be divided by estimation of its goodness, rather than the largeness of its measure, it often happening that one acre of some sort of land was equivalent to a thousand other acres. Now the men that were sent, which were in number ten, traveled all about, and made an estimation of the land, and in the seventh month came to him to the city of Shiloh, where they had set up the tabernacle.