To go up to war against them - Supposing that they had built this altar in opposition to that which Moses, by the command of God, had erected, and were consequently become rebels against God and the Israelitish constitution, and should be treated as such. Their great concern for the glory of God led them to take this step, which at first view might appear precipitate; but, that they might do nothing rashly, they first sent Phinehas and ten princes, one out of each tribe, to require an explanation of their motives in erecting this altar.

Thus saith the whole congregation of the Lord,.... By whom they were sent, and whom they represented; and they do not call them the congregation of Israel, but of the Lord, because it was not on a civil but religious account they were come, and not to plead their own cause, but the cause of God; and not so much to show a concern for their own honour and interest as for the glory of God:

what trespass is this that ye have committed against the God of Israel; they took it for granted that they had committed a sin, and that so great, they were not able to express the greatness of it in all its aggravated circumstances, and plainly suggest it was idolatry; which was too premature, when as yet they had not inquired into it; but their zeal for God, and his honour, hurried them into this hasty step:

to turn away this day from following the Lord; they intimate, that they had begun a revolt from the worship of God, which is aggravated by their falling into it so soon, having received so many favours from God, and had so lately seen such wonderful appearances of his power and goodness, and had just had such excellent instructions, exhortations, and cautions given them by Joshua, when he dismissed them:

in that ye have built you an altar; which they supposed was to offer sacrifices upon; whereas there was to be but one altar, and that in the place which the Lord should choose to put his name in, and which he had now chosen, where all sacrifices were to be brought and offered up; see Exo 20:24,

that ye might rebel this day against the Lord? against the commandment of the Lord expressed in the places referred to, which they charge with rebellion against himself, a very high and heavy charge indeed! but they should first have inquired whether they were guilty of the trespass, or with what view they had built the altar, whether for sacrifice, or for some other use; but they took it for granted it was for sacrifice.

CONTENTION THEREUPON. (Jos. 22:11-29)

and the children of Israel heard say--Fame speedily spread intelligence of what the trans-jordanic tribes had done. The act being suspected of some idolatrous design, the tribes rose in a mass, and repairing to the tabernacle at Shiloh, resolved to declare war against the two tribes and a half as apostates from God. On calmer and more mature consideration, however, they determined, in the first instance, to send a deputation consisting of the son of the high priest, and ten eminent persons from each tribe, to make inquiry into this rumored rebellion against God (Deu 13:13-15). The quality of the deputies evinced the deep solicitude that was felt on the occasion to maintain the purity of the divine worship throughout Israel. In the presumptive belief that the two tribes and a half had really built an altar, the deputies expressed astonishment at their so soon falling into such a heinous crime as that of violating the unity of divine worship (Exo 20:24; Lev 17:8-9; Deu 12:5-13). They reminded their eastern brethren of the disastrous consequences that were entailed on the nation at large by the apostasy at Peor and by the sin of Achan, and finally exhorted them, if they felt the want of the tabernacle and altar and repented of their rash choice in preferring worldly advantages to religious privileges, to remove to the western side of the Jordan, where all the tribes would form a united and obedient community of worshippers.