“And when they came unto the borders of Jordan, that are 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 Jordan, a great altar to see to.”
King James Version (KJV)
22:10 Built an altar - About that time when they came to them, they designed it, and as soon as they were got over Jordan, which was in a very little time, they effected and perfected it. They built it, no doubt, on their own side of the water: for how could they build on other men's land, without their consent? And it is said, in the following verse, to be over against the land of Jordan. Nor would there have been cause to suspect that it was designed for sacrifice, if they had not built it among themselves.