Deuteronomy 4:41
Then Moses severed three cities on this side Jordan toward the sunrising;
Then Moses severed three cities,.... To be cities of refuge, according to the command of God, Numbers 35:14 this he did when he had conquered the two kingdoms of the Amorites, that God had given them for an inheritance to the tribes of Reuben and Gad, and the half tribe of Manasseh, Deuteronomy 4:38 though Jarchi says, and so other Jewish writers, that persons were not received into them until the three cities appointed in the land of Canaan were separated for the like use;
See Gill on "Numbers 35:14" and these were,
on this side Jordan, toward the rising sun; on that side of the river on which the plains of Moab lay, and the kingdoms of the Amorites, and to the east of Jordan: so Jarchi remarks,
"on that side which is on the east of Jordan;''
see Joshua 20:8.