Numbers 10:28 (NKJV)

The children of Israel were brought out of their captivity from Egypt in the order of their armies:

²⁸ Thus was the order of march of the children of Israel, according to their armies, when they began their journey.

And these armies were supposed to stand in unity as one united body, that will fight, sacrifice, serve God, support each other, and do what ever it takes until all the tribes’ had possessed the portion of their promised land which was granted unto them.

Numbers 32:1-12 (NKJV)

Reuben & Gad decides to choose their promised land before the crossing of the river Jordan:

32 Now the children of Reuben and the children of Gad had a very great multitude of livestock; and when they saw the land of Jazer and the land of Gilead, that indeed the region was a place for livestock, 

² the children of Gad and the children of Reuben came and spoke to Moses, to Eleazar the priest, and to the leaders of the congregation, saying, 

³ “Ataroth, Dibon, Jazer, Nimrah, Heshbon, Elealeh, Shebam, Nebo, and Beon, 

⁴ the country which the Lord defeated before the congregation of Israel, is a land for livestock, and your servants have livestock.”

 ⁵ Therefore they said, “If we have found favor in your sight, let this land be given to your servants as a possession. Do not take us over the Jordan.”

Moses gets angry at Reuben & Gad, because of their evil & selfish motive,

They were trying to avoid going to war with the rest of the tribes….

⁶ And Moses said to the children of Gad and to the children of Reuben:

“Shall your brethren go to war while you sit here? 

⁷ Now, why will you discourage the heart of the children of Israel from going over into the land which the Lord has given them? 

Moses compares Reuben and Gad’s motive to the sin of the 10 spies, who brought a negative report which discouraged Israel from going into their promise land:

⁸ Thus your fathers did when I sent them away from Kadesh Barnea to see the land. 

⁹ For when they went up to the Valley of Eshcol and saw the land, they discouraged the heart of the children of Israel, so that they did not go into the land which the Lord had given them. 

¹⁰ So the Lord’s anger was aroused on that day, and He swore an oath, saying, 

¹¹ ‘Surely none of the men who came up from Egypt, from twenty years old and above, shall see the land of which I swore to Abraham, Isaac, and Jacob, because they have not wholly followed Me, 

¹² except Caleb the son of Jephunneh, the Kenizzite, and Joshua the son of Nun, for they have wholly followed the Lord.’

Numbers 32:13-17N (NKJV)

¹³ So the Lord’s anger was aroused against Israel, and He made them wander in the wilderness forty years until all the generation that had done evil in the sight of the Lord was gone. 

Moses condemns Reuben and Gad because of their evil motive and desire…

¹⁴ And look! You have risen in your fathers’ place, a brood of sinful men, to increase still more the fierce anger of the Lord against Israel. 

¹⁵ For if you turn away from following Him, He will once again leave them in the wilderness, and you will destroy all these people.”

Reuben and Gad finally decide to go to war, so that the other tribes may also possess their promised land:

¹⁶ Then they came near to him and said: “We will build sheepfolds here for our livestock, and cities for our little ones,

¹⁷ but we ourselves will be armed, ready to go before the children of Israel until we have brought them to their place; and our little ones will dwell in the fortified cities because of the inhabitants of the land.