John Gill Bible Commentary

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.