John Calvin Commentary Joshua 22:10

"And when they came unto the region about the Jordan, that is in the land of Canaan, the children of Reuben and the children of Gad and the half-tribe of Manasseh built there an altar by the Jordan, a great altar to look upon." — Joshua 22:10 (ASV)

And when they came to the borders, etc. The history here is particularly deserving of notice. The two and a half tribes, intending to set up a memorial of common faith and brotherly unity, allowed themselves, out of thoughtless zeal, to adopt a method that was justly suspected by their brothers.

The ten tribes, thinking that God's worship was violated with irreverent boldness and recklessness, were inflamed with holy anger and took up arms against their own relatives; nor were they pacified until they had received full satisfaction.

The motive for setting up the altar was right in itself. For the aim of the people of Reuben, Gad, and Manasseh was to testify that although a river separated them from their brothers, they were nevertheless united with them in religion and shared a mutual agreement in the teaching of the Law. It was far from their intention to make any changes whatsoever in God's worship. However, they sinned gravely by attempting something new without any regard for the high priest or consulting their brothers, and in a way that was very likely to be misunderstood.

We know how strictly the Law prohibited two altars (Exodus 20:24), for the Lord wished to be worshipped in one place only. Therefore, when at first glance everyone was immediately led to think that they were building a second altar, who would not have judged them guilty of sacrilege in creating a corrupt form of worship, contrary to God's Law?

Since, then, their action could be considered wrong, they should, at least, in such a great and serious matter, have consulted their brothers. They were especially wrong in failing to consult the high priest, from whose lips God's will was to be determined. They were, therefore, blameworthy because, as if they were alone in the world, they did not consider what offense might arise from the newness of their example.

Therefore, let us learn not to attempt anything hastily, even if it seems blameless. Let us always pay careful attention to the admonition of St. Paul (1 Corinthians 6:12; 1 Corinthians 10:23) that it is necessary to consider not only what is lawful, but also what is beneficial. Especially, let us carefully avoid disturbing devout minds by introducing any kind of novelty.