Well, the book of Joshua at the textual level uses this phrase: "all Israel," "all of Israel," over sixteen times, and the idea of this is to drive home to the reader the unity and the cohesive nature of the binding requirements the Lord is placing upon Israel. Not only that, the notion that the Lord is with, not only Joshua, the Lord is with all of Israel, and as such, all of God's promises and blessings are promised to Israel, as are God's warnings, and is the contingent nature of Israel's response of obedience in faith to the Lord's commands. So, this phrase "all Israel" then serves at the textual level to hold all of Israel accountable before the Lord as they move into the Promised Land. This will not be done by a single figure. This will be an event in which the entirety of the nation of Israel is to take place. Now, when we look at this thematically, a story that very clearly pops to mind is the story of the sin of Achan in Joshua 7... And interestingly when we look at the story of Achan, we see all of Israel held accountable for the sin of Achan. Now, symbolically, Achan and his entire family, and everything that he owned is destroyed. So, in some sense Achan pays for his sin through the death of his family and himself. However, all of Israel is called on to bear witness to this, and all of Israel cannot move forward until the sin of Achan is dealt with. Now, all of Israel is also called to remember the sin of Achan. This is not something that can be forgotten and dusted and swept under the carpet. Israel must live with this before itself, and this is seen in two different ways. The first is that the name "Achan" is closely associated with the noun achar, right, which means "trouble," which, when we get into 1 Kings, you see King Ahab calling the prophet Elijah "a troubler," right, to which Elijah turns around and calls Ahab the troubler. Either way, in the Hebrew language and throughout the Hebrew story, this notion of achar, related etymologically to Achan, lives on, is remembered as the troubler. So, all of Israel is called to constantly remember the sin of Achan through the use of this name. Secondly, we see that the sin of Achan is to be memorialized, in the same way that the crossing of the Jordan was memorialized, with the heaping of stones, and in the same ways we'll see the Transjordan tribes raise a stone to express their unity with the other tribes, so too is the sin of Achan held before all of Israel in a physical monument, which is this stone pile raised to commemorate the sin of Achan. And interestingly, here the text tells us that in his sin Achan has "crossed over." What has he crossed over? In the same way the Israelites crossed over the Jordan River, Achan has crossed over. He has violated the covenant commands of the Lord in disobeying God and hiding loot. So, Israel, all of Israel, is called to remember, through the use of these visible symbols, Israel is called to remember the sin of Achan. All of Israel had to deal with Achan's sin. All of Israel stands before the Lord. And all of Israel must give account for her obedience or lack thereof. There are two other ways in which all of Israel is highlighted. As Israel moves into the Promised Land, all of Israel is to be cared for, not some of Israel, not the leaders, not a particular class or tribe. All of Israel is made much of in the book of Joshua. Two examples in which the Lord cares for all of Israel, not just some of Israel, can be found in Deuteronomy 25 and Leviticus 25. In Deuteronomy 25, we have Levirate marriage vows. In this case, should a woman's husband die, the nearest brother of her husband is to take her as his wife in order to perpetuate the family name. And in this we see, as Israel moves into the Promised Land, the least of the community, those who are most vulnerable, those who are most likely to be forgotten or marginalized, are to be cared for. There are provisions made for all of Israel. Secondarily, we see in Leviticus 25, here the land is cared for. A major ingredient and component of Israel was the geographical location—their land. This is the inherited, promised, covenantal blessing of the land. The land is to be cared for. So, should a member of Israel lose their land due to hard times financially or some disadvantageous situation, their nearest kin was to step in and care for them. These are just two examples of which the Lord has continually made provision, not for some of Israel, but for all of Israel.