BT Ḥul 111b(45) :הוו יתבין חד מהאי גיסא דמברא דסורא וחד מהאי גיסא דמברא‏ : they were sitting one on one side of the (canal) crossing and one on the other side of the crossing
See the entire entry for maˁbar, maˁbrā n.m. crossing