“And it came to pass a long time after that the LORD had given rest unto Israel from all their enemies round about, that Joshua waxed old and stricken in age.” (Joshua 23:1)
We don’t know how old Joshua was when he became leader of Israel, but we know he was old enough to lead the army and be one of the twelve spies. Assuming he was the same age as Caleb, he would have been approximately eighty. He was now approaching a hundred and ten, which means he was probably the leader for about thirty years. Declining health and age made it clear he would soon have to give up his position.
“And Joshua called for all Israel, and for their elders, and for their heads, and for their judges, and for their officers, and said unto them, I am old and stricken in age: And ye have seen all that the LORD your God hath done unto all these nations because of you; for the LORD your God is he that hath fought for you. Behold, I have divided unto you by lot these nations that remain, to be an inheritance for your tribes, from Jordan, with all the nations that I have cut off, even unto the great sea westward.” (Joshua 23:2-4)
Gathering Israel together, Joshua announced his impending retirement. He began his speech with a brief summary of what God had done for them, destroying the power of the nations that had occupied the land, and fighting for them. As a result they were able to divide the land among the different tribes and families, even though many pockets of resistance remained.
“And the LORD your God, he shall expel them from before you, and drive them from out of your sight; and ye shall possess their land, as the LORD your God hath promised unto you. Be ye therefore very courageous to keep and to do all that is written in the book of the law of Moses, that ye turn not aside therefrom to the right hand or to the left; That ye come not among these nations, these that remain among you; neither make mention of the name of their gods, nor cause to swear by them, neither serve them, nor bow yourselves unto them: But cleave unto the LORD your God, as ye have done unto this day.
For the LORD hath driven out from before you great nations and strong: but as for you, no man hath been able to stand before you unto this day. One man of you shall chase a thousand: for the LORD your God, he it is that fighteth for you, as he hath promised you. Take good heed therefore unto yourselves, that ye love the LORD your God.” (Joshua 23:5-11)
Continued victory did not depend on Joshua’s leadership. God would drive out the pockets of resistance just as he had in giving them possession of the land. It would be up to the people to continue to serve God, as Joshua would not be there to lead them. It would be essential that they not allow themselves to assimilate the customs of the people that still remained, continuing to devote themselves to the Lord. It would not be necessary to acquiesce to their demands to maintain peace.
Their victories had not been the result of superior forces, but of God fighting for them, and that would continue if they followed him. As long as God fought for them, even thousand to one odds were not insurmountable.
“Else if ye do in any wise go back, and cleave unto the remnant of these nations, even these that remain among you, and shall make marriages with them, and go in unto them, and they to you: Know for a certainty that the LORD your God will no more drive out any of these nations from before you; but they shall be snares and traps unto you, and scourges in your sides, and thorns in your eyes, until ye perish from off this good land which the LORD your God hath given you.” (Joshua 23:12-13)
The caveat to this was that if they began to assimilate these other peoples by intermarrying and adopting their customs, then God would no longer drive them out. Instead they would become a source of conflict and ongoing irritation, eventually leading to the loss of the land.
“And, behold, this day I am going the way of all the earth: and ye know in all your hearts and in all your souls, that not one thing hath failed of all the good things which the LORD your God spake concerning you; all are come to pass unto you, and not one thing hath failed thereof.” (Joshua 23:14)
Like every living thing on the Earth, Joshua was going to die, but the people knew that every good thing God had promised had been fulfilled. Nothing had been left out.
“Therefore it shall come to pass, that as all good things are come upon you, which the LORD your God promised you; so shall the LORD bring upon you all evil things, until he have destroyed you from off this good land which the LORD your God hath given you. When ye have transgressed the covenant of the LORD your God, which he commanded you, and have gone and served other gods, and bowed yourselves to them; then shall the anger of the LORD be kindled against you, and ye shall perish quickly from off the good land which he hath given unto you.” (Joshua 23:15-16)
They could see how completely God had fulfilled his promises for obedience. His promises for judgment if they disobeyed were equally certain. If they broke their contract with God, worshipping other gods, he would expel them from the land in short order. It would be up to them to serve God.