Charles Ellicott Commentary Numbers 21:11

"And they journeyed from Oboth, and encamped at Iyeabarim, in the wilderness which is before Moab, toward the sunrising." — Numbers 21:11 (ASV)

At Ije-abarim— This word seems to denote the heaps (or, ruins) of passages or of coast or river lands — i.e., of districts bordering upon the sea or a river. It is called Iim or Iyim simply in Numbers 33:45.