Complete Commentary on the Whole Bible, by Matthew Henry, at sacred-texts.com
(Num 32:1-5) The tribes of Reuben and Gad request an inheritance on the east of Jordan.
(Num 32:6-15) Moses reproves the Reubenites and Gadites.
(Num 32:16-27) They explain their views, Moses consents.
(Num 32:28-42) They take possession of the land to the east of Jordan.
Here is a proposal made by the Reubenites and Gadites, that the land lately conquered might be allotted to them. Two things common in the world might lead these tribes to make this choice; the lust of the eye, and the pride of life. There was much amiss in the principle they went upon; they consulted their own private convenience more than the public good. Thus to the present time, many seek their own things more than the things of Jesus Christ; and are led by worldly interests and advantages to take up short of the heavenly Canaan.
The proposal showed disregard to the land of Canaan, distrust of the Lord's promise, and unwillingness to encounter the difficulties and dangers of conquering and driving out the inhabitants of that land. Moses is wroth with them. It will becomes any of God's Israel to sit down unconcerned about the difficult and perilous concerns of their brethren, whether public or personal. He reminds them of the fatal consequences of the unbelief and faint-heartedness of their fathers, when they were, as themselves, just ready to enter Canaan. If men considered as they ought what would be the end of sin, they would be afraid of the beginning of it.
Here is the good effect of plain dealing. Moses, by showing their sin, and the danger of it, brought them to their duty, without murmuring or disputing. All men ought to consider the interests of others as well as their own; the law of love requires us to labour, venture, or suffer for each other as there may be occasion. They propose that their men of war should go ready armed before the children of Israel into the land of Canaan, and that they should not return till the conquest of Canaan was ended. Moses grants their request, but he warns them of the danger of breaking their word. If you fail, you sin against the Lord, and not against your brethren only; God will certainly reckon with you for it. Be sure your sin will find you out. Sin will surely find out the sinner sooner or later. It concerns us now to find our sins out, that we may repent of them, and forsake them, lest they find us out to our ruin.
Concerning the settlement of these tribes, observe, that they built the cities, that is, repaired them. They changed the names of them; probably they were idolatrous, therefore they should be forgotten. A spirit of selfishness, of seeking our own, not the things of Christ, when each one ought to assist others, is as dangerous as it is common. It is impossible to be sincere in the faith, sensible of the goodness of God, constrained by the love of Christ, sanctified by the power of the Holy Ghost, and yet be indifferent to the progress of religion, and the spiritual success of others, through love of ease, or fear of conflict. Let then your light so shine before men, that they may see your good works, and glorify your Father which is in heaven.