John Gill Bible Commentary

And if we have not rather done it for fear of this thing,.... So far they suggest were they from doing this, in order to turn from the pure worship of God, and introduce idolatrous worship, that it was to guard against everything of that kind for the future; and through fear of it, and anxiety and distress of mind, lest some time or another there should be any temptation to it in their posterity, had they built this altar: saying, in time to come your children might speak unto our children; or "tomorrow" (m), in a short time after your heads, and ours, are laid in the grave, your posterity will accost us: saying, what have you to do with the Lord God of Israel? you are aliens and strangers from the commonwealth of Israel, live in a foreign land, and not in the land, of Canaan; are separated from us by the river Jordan, are a different people from us, and have nothing to do with the tabernacle of the Lord, and the service of it, or with the altar of the Lord, to offer sacrifice on it. Now as they returned to their own country, or when got there, such anxious thoughts and fears rose up in their minds, which they communicated to one another, and thought of this expedient to prevent what would be so fatal to their posterity. The Targum is,"you have no part in the Word of the Lord God of Israel;''see Joh 13:8. (m) "cras", Pagninus, Montanus, &c.